Check Engine Light

[ledzilla]

My check engine light came on the other day. I went over to the local Autozone and had them check the codes. This is what I got:

Code P1151

Definition -- Lack of O2 switches - Bank 2 Sensor 1

Explanation -- ECM could not adjust fuel trim because of a lean or rich condition

Probable Causes --
1) Fuel pressure high or low
2) MAF sensor dirty/defective
3) Vacuum leak on engine
4) Leaking fuel injector or fuel pressure regulator

I'm sure it's not #2, since there was an improvement after I cleaned the MAFS. I'm also sure it isn't #4 since I don't smell any gas (I've had a fuel leak on my old Lincoln, so I know the situation). If anyone knows what else could be done, it would be a great help. BTW, when the light first came on there was no difference in the way the car behaved. After a few days, though, I seem to be getting a rough idle and some surging (?) when accelerating (not WOT).

[Zack]

Clear the code, fill up with Amoco premium, go beat the snot out of it.

[Black_Noise]

it sounds like the 02 sensor is bad

[Local Boy]

Fuel filter? Have you changed yours yet?

Good Luck...

ALOHA

[ledzilla]

New fuel filter (installed Sat) and clean MAF sensor (also Sat). Been using Amoco Ultimate since I bought the car. Only other gas used is Shell V-Power. I'll check out costs for O2 sensors. Not thrilled by that prospect, though.

[chader]

New fuel filter (installed Sat) and clean MAF sensor (also Sat). Been using Amoco Ultimate since I bought the car. Only other gas used is Shell V-Power. I'll check out costs for O2 sensors. Not thrilled by that prospect, though.
Did the mil come on after you cleaned the MAF?

[ledzilla]

No, the light came on several days before cleaning it. I was hoping that the new filter and the cleaning would clear it out, but I was wrong.

[magindat]

No, the light came on several days before cleaning it. I was hoping that the new filter and the cleaning would clear it out, but I was wrong.

You need to clear it and see if the problem persists to throw it again.

[ledzilla]

How do you clear it?

[Dragcity]

To clear it you must hit the "Maximum Speed Achieved" Function, which is programmed in the EEC. Only one way to do that.

Only Kidding!

Disconnect battery terminals (Clean and dialectric grease while you are at it). Leave off for about 20 minutes. I usually clean the Throttle body, linkage and MAF while I wait. Wipe down the fender wells and plastic shrouds with silicone, clean things up, check all fluids....

Re-attach the terminal connectors. Start engine wihtout any accessories runing. Let her warm to normal op temp. Take her for a spin. See what you get. Codes may or may not come back.

[ledzilla]

I already activated that function on I-88... hehehe :D

Thanks for the info. I feel that was something I should've known already. I did the reset and the beast is out in the company lot warming up right now (yes, I have tools in the trunk... always have tools in the trunk). I suppose we'll see how it goes by time I get home.

[Blackened300a]

It may take a few miles and keyturns to really make sure that the code doesnt come back. Sometimes it may even take up to a hundred miles of driving to be sure the code is cleared.
When you said the idle surged, did you check all your intake tube clamps? Also make sure your connections on your MAF are clean and plugged in tight.

[Pat]

Auto Zone should be able to clear the code. Ask 'em.

[thePunisher]

a maf problem would not cause a bank specific lean or rich problem....if maf were faulty both banks would have similar issues..same rule goes for fuel filters, pumps etc....the likely cause here is an o2 senser that intermittenly stops switching...it is most likely worn/damaged. i see this all the time at the dealer. as stated above you dont need the parts store to clear the code. just disconnect the battery for a few minutes.....this will clear the code and the KAM (keep alive memory)

[ledzilla]

Ok. I did a battery disconnect after cleaning the MAF sensor. The light came back on after driving about 4 or 5 miles. That evening I replaced the fuel filter, but I didn't disconnect the battery again until around the time I got off of work. I went a few more miles and ran the motor for a while longer this time and the light hasn't come back on. I'm not assuming that the problem is solved, so I'll keep an eye on it. If it truly is a faulty O2 sensor, can you tell me which one it is based on the code description? Or would I be better off replacing both sensors?

BTW, I was checking out O2 sensors online to get an idea of the cost. Any recommendations on manufacturers, or just go with Motorcraft?

[thePunisher]

it is the passenger side, upstream sensor. definitely get a ford/motorcraft senser!!!!!!!!!

[Dragcity]

Nice work everyone. Another members problem solved. (or at least narrowed down significantly)

[ledzilla]

Well, since the light came back on while driving to work, looks like I'll be buying a new upstream O2 sensor. Thanks for the info! Just out of curiosity, since I have never needed to replace an O2 sensor in my life (they never went bad in my Lincoln over the 8 years I drove it), is there any difficulties that will be encountered, or is it a simple fix with no or minor complications?

[thePunisher]

they simply thread out.

[ledzilla]

I meant is there a best way to reach it, are there plugs for the sensor wires or is there splicing to do.... That kind of thing. Chances are that I'll have to do this on a Sunday, so I don't want any surprises that'll require a trip to the store. I'd like to have everything I need at hand before taking anything apart.

[thePunisher]

no splicing. just male/female connectors....

[ledzilla]

So, it took more over two months to finally replace that O2 sensor. And much to my surprise, it didn't solve the problem. Between the last post on this thread and now, the car started to occasionally run on the rather rough side. So on Sunday morning I replaced the sensor and reset the computer. I had some errands to run so I took off to get them done, and as I was on my way back home the Check Engine light came back on. Yesterday during lunch I stopped at an Autozone down the street from where I work and had them check the codes. Not only is the original P1151 trouble code still there (see first post for detail), but now there's a second code (as appears on the printout from AZ):

Code - P0152

Definition:
H02S-21 circuit condition (heated oxygen sensor bank 2 sensor 1)

Explanation:
The powertrain control module uses the oxygen sensor to calculate the the air/fuel ratio in the exhaust

Probable Causes:
1. Oxygen sensor defective
2. Fuel system running very rich or lean - check other codes first
3. Engine misfire condition - repair
4. Fuel pressure very high or low - fuel pump or pressure regulator

So I replaced the upstream sensor on the right side with a Motorcraft sensor (made in Japan, wouldn't you know). And the problem still persists. If anyone can think of a solution, I'd be more than happy to know.

[BLACKMARAUDER04]

Take it to a dealer to be fixed $100 plus parts for first hour.

[thePunisher]

you replaced the wrong senser...bank 2 is the driver side. you have codes for bank 2 upstream senser. and i still think the 02 is your problem. replace the driver side upstream senser. 99 out of 100 times when i see those codes at the dealer the o2 is faulty!

[captain]

both the codes you throw tell us to look at 2 other codes...
0152 sends you to 0132
1151 sends you to 1130
here is P01130 and the next post will be PO132
good luck
P1130 - Lack of HO2S-11 Switch, Fuel Trim at Limit The HEGO Sensor is monitored for switching. The test fails when the HO2S fails to switch due to circuit or fuel at or exceeding a calibrated limit.
Electrical:
Short to VPWR in harness or HO2S
Water in harness connector
Open/Shorted HO2S circuit
Corrosion or poor mating terminals and wiring
Damaged HO2S
Damaged PCM
Fuel System:
Excessive fuel pressure
Leaking/contaminated fuel injectors
Leaking fuel pressure regulator
Low fuel pressure or running out of fuel
Vapor recovery system
Induction System:
Air leaks after the MAF
Vacuum Leaks
PCV system
Improperly seated engine oil dipstick
EGR System:
Leaking gasket
Stuck EGR valve
Leaking diaphragm or EVR
Base Engine:
Oil overfill
Cam timing
Cylinder compression
Exhaust leaks before or near the HO2S(s)A fuel control HO2S PID switching across 0.45 volt from 0.2 to 0.9 volt indicates a normal switching HO2S.

[captain]

P0132 - HO2S Sensor Circuit High Voltage (HO2S-11) The HO2S Sensor Signals are monitored for an over voltage fault. The code is set when HO2S signal voltage is 1.5 volts or greater.
HO2S Signal Circuit shorted to Heater Power inside of HO2S sensor.
HO2S Signal Circuit shorted to VPWR or VREF in harness.
PCM failure.An HO2S PID switching across 0.45 volt from 0.2 to 0.9 volts indicates a normal switching HO2S. HO2S PID voltage of 1.5 volts or greater indicates a short to power.

[thePunisher]

a faulty senser can read over 1.0v not necessarily a short. all he has to do is replace the bad sensor on the correct bank. he replaced the passenger (bank 1) sensor........his codes are for bank 2.

[DirtyDog]

I had simular problem. Try this, with engine running, unplug the MAF sensor and see if there is any difference in the idle. I was blowing 02 sensor codes for months and could not find it. 02's checked OK and MAF checked OK, and running lean. The MAF was within tolerances. When unpluged it ran the same as with it plugged in. Replaced it and everything was fixed and no more codes. It was running lean prior, the new MAF brought the air/fuel mix right on.


Dave

[thePunisher]

he has bank 2 specific codes. if he had codes for both banks the maf could be a possible culprit. but the maf cannot cause a bank specific problem. any issues caused by a faulty maf affect both banks.

again...he has to replace the correct o2 sensor. we dont have to look too deep here guys.....

[Paul T. Casey]

[QUOTE=ledzilla;616913]
So I replaced the upstream sensor on the right side with a Motorcraft sensor QUOTE]

I can't for the life of me, ever figure out why one would change only one sensor. Replace in pairs (front or back) as a minimum, and preferably all four. If this doesn't solve your problem, look for vacuum leaks or a faulty fuel pump. When mine went bad it caused a over rich condition, probably due to over-pressure.

[thePunisher]

[quote=ledzilla;616913]
So I replaced the upstream sensor on the right side with a Motorcraft sensor QUOTE]

I can't for the life of me, ever figure out why one would change only one sensor. Replace in pairs (front or back) as a minimum, and preferably all four. If this doesn't solve your problem, look for vacuum leaks or a faulty fuel pump. When mine went bad it caused a over rich condition, probably due to over-pressure.

the rear oxygen sensors are only catalyst montitors. they dont in any way affect fuel trims or driveability. replacing them is simply throwing money away.

[DirtyDog]

he has bank 2 specific codes. if he had codes for both banks the maf could be a possible culprit. but the maf cannot cause a bank specific problem. any issues caused by a faulty maf affect both banks.

again...he has to replace the correct o2 sensor. we dont have to look too deep here guys.....


Mine would blow right side one time and then it would show the other side and some times both at the same time. It was such a minor error it would pass the test some times. I did not have to replace the 02's, but did a week later because I bought them when I got MAF.

[ledzilla]

Alrighty. Thanks for the input guys. I replaced the passenger side because someone in an earlier post on this thread said it was passenger side. I guess I'll order another sensor and replace the driver side as well and see where it goes from there. Rebate check to the rescue! hehe

[thePunisher]

Alrighty. Thanks for the input guys. I replaced the passenger side because someone in an earlier post on this thread said it was passenger side. I guess I'll order another sensor and replace the driver side as well and see where it goes from there. Rebate check to the rescue! hehe

i am very sorry. it was me who misinformed you about which side the code was for. i appologize. i guess i had my head up my azz that day..........:shake::depress: i may be mistaken but i think both sides use the same upstream sensor....you can swap them if you still have your old sensor....

[ledzilla]

Actually, I had to toss the one I pulled. I couldn't get it out, that is, until I ended up busting the wires. The wires were run between some sort of cable run and the underside of the cabin. There wasn't enough room for the plug to fit, and while I was fiddling with trying to get the cable run unplugged, I busted a couple of wires on the O2 sensor. So, I just cut the remaining wires and chucked it in the trash. It would have been nice if I didn't break it, though, because the moron driving the UPS delivery truck couldn't find my house. I was expecting the new sensor on Friday. Now I have to wait until Tuesday to get it, but due to my life's scheduling, I can't install it until next Sunday. And my poor MM is running like it's about to die now. It gets close to stalling when I hit the gas. It's been slowly getting worse since the check engine light came on a couple months ago. I really would have liked to put the old, working one in until I had the chance to install the other new one.

[lucenti]

had a similar problem 1 year ago. o2 sensor codes. replaced both sensors problem still persisted. btw i installed wagner o2's which i bought from local parts store. checked for vacume leaks, took readings from MAF with engine on, checked ok. funny thing i left brooklyn for a few dayzz and no codes. must have put 250 miles on. as soon as i re-entered brooklyn within 20 minutes code poped up. ok so maybe i should move and tht will clear the problem. get into a conversation with a friend and he informs me that the MAF was calibrated for a different part of the country. got to love these conversations :stupid:.. on a gut hunch, i replace the MAF and problem was no more! hope this helps

BTW they sell a sloted socket just for o2's

[Glenn]

Perhaps someone on this thread can tell me which side is Bank 1 on a 1996 Ranger with the 3.6 V-6 engine. I seem to also have a bad o2 sensor.

Thanks,

Glenn

[thePunisher]

on all ford engines...bank 1 is the pass side. bank 2 is driver.

[Glenn]

Thanks very much,

Glenn

[lucenti]

redundent conversation

:D

may want to get a bike with peddles:rofl:

[ledzilla]

Well, I installed the new sensor... driver's side this time... And the car is running MUCH better. Ran some Sea Foam and it started running a little better still. However, before and after the Sea Foam, I noticed that it's not running quite right at WOT. Instead of a steady power curve during acceleration, it seems to cut back a little at random intervals. Someone suggested that it could be missing. I still have factory COPs and connecotrs, but I've installed new plugs... With the problems I had from the bad sensor, could the plugs be fouled?

[thePunisher]

if theyre fouled its not from the faulty sensor...not in this case at least. the pcm goes into open loop at WOT and ignores the o2's. disconnect the battery to clear the KAM. this will reset all your fuel trims. what plugs did you use....?

[ledzilla]

Before I sterted the car back up with the new sensor I left the battery unplugged for about 15 minutes. Would I need to reset it again? If I remember correctly, I used Motorcraft plugs.

[thePunisher]

nope that should be ok then.....

[ledzilla]

Well, I have to change the oil this month. I usually take it to the local Ford shop since I hate dealing with the filter on it (and it gets done for about $33). While it's there I'll ask them if they can figure it out, supposing they won't take all day with it.

[ledzilla]

Well, the other day my check engine light came on... The next day went to AZ and had them check the code... P0307 - Misfire, Cylinder #7. The next day, the check engine light was gone and the car was running better. I am honestly confused. Does this mean that the COP was running improperly? If so, should I get it replaced anyway?

[Glenn]

The dreaded #7 cylinder is the one that causes problems. Did you ever overheat the engine even for a short time?

Glenn

[ledzilla]

Actually, yes. Winter of '06-'07. Had an air bubble in the cooling system and had it overheat almost daily... Not a complete overheat, but it did get on the hot side before dropping back down to normal. The last day or two before having the system flushed it did get way too hot.

[Glenn]

You need to check the compression in #7 cylinder. I would guess that it is below 90 psi. This may be your problem. The valve seats may have been warped due to excessive heat.

Glenn :burnout:

[ledzilla]

Oh man. That sounds like an expensive repair. Well, I'll probably have it checked soon.

[ledzilla]

Well, I went and just bought a new Motorcraft COP and I put it in today... In the rain... Anyway, that solved the problem. It's running really smooth now, and I didn't realize how much power I had lost. I had a little trouble with the rain while I was getting used to all those fabulous horses again.

[ledzilla]

Well, within a week or so of replacing that COP, I started to feel another one go. Feeling that same hesitation at WOT. So today I ordered seven more COPs. Believe it or not, I was able to order them all from Amazon.com and get free shipping. I should have them by Thursday. And they're all Motorcraft, too. Bought them for less than $50 each. Had I known I could get them from Amazon.com, I could have saved almost $20 for the first one.