Lean Off Idle

[Paul T. Casey]

Been popping a CEL lately, forget the code number, but it's for Lean Off Idle, Bank 1 (or 2) sensor 1. I know banks and sensors, however I'm not sure it's a bad O2 sensor. I also have a ping if I rap it off idle. As you all know, I have a few miles (157K). How long do these other emission parts (IAC, TPS, Knock sensor, etc.) last. Is there a way of testing each of those? I'd hate to have to replace stuff for no reason.

[TooManyFords]

Been popping a CEL lately, forget the code number, but it's for Lean Off Idle, Bank 1 (or 2) sensor 1. I know banks and sensors, however I'm not sure it's a bad O2 sensor. I also have a ping if I rap it off idle. As you all know, I have a few miles (157K). How long do these other emission parts (IAC, TPS, Knock sensor, etc.) last. Is there a way of testing each of those? I'd hate to have to replace stuff for no reason.

First thing I would do is disconnect the battery ground for 5 minutes so that the PCM forgets any long term fuel trim corrections. Let it learn all over again to compensate for aging components.

Also, get some injector cleaner and run through a couple tanks of that with some good 93. Wherever you're getting your gas now, go somewhere else to eliminate the fuel source as the cause.

And finally, a little Seafoam treatment in the gas to help break up carbon deposits.

Report back in 2 weeks or 4 tanks fulls, whichever comes sooner.

John

[HwyCruiser]

Maybe time to clean your MAF too.

[Stranger in the Black Sedan]

Whooo that's alot of miles on an MM. Good to know they are still going at that mileage. How did you manage to drive so many miles so soon?

[Paul T. Casey]

First thing I would do is disconnect the battery ground for 5 minutes so that the PCM forgets any long term fuel trim corrections. Let it learn all over again to compensate for aging components.

Also, get some injector cleaner and run through a couple tanks of that with some good 93. Wherever you're getting your gas now, go somewhere else to eliminate the fuel source as the cause.

And finally, a little Seafoam treatment in the gas to help break up carbon deposits.

Report back in 2 weeks or 4 tanks fulls, whichever comes sooner.

John

Forgot about Seafoam, I'm thinking carbon on piston tops. Thanks

[Paul T. Casey]

Maybe time to clean your MAF too.

Done. thanks

[Paul T. Casey]

Whooo that's alot of miles on an MM. Good to know they are still going at that mileage. How did you manage to drive so many miles so soon?

I am driven! Seriously, I work on the road. My wife also does. In the past 2 weekends, I've driven from Huntsville Al to Rogkford Il and back, and from Huntsville to Marion IL and back. I do 75 miles a day here for work. When I want to go somewhere, I go. I've driven across the good ole USA (backroads) once. Did I mention I've done at least one documented burnout in 37 states? How about the fact I have more than 300 timeslips from legal drag raging. Yeah, I wouldn't sweat the mileage thing. BTW, I have an early build '03 with STOCK axles. Just thought I'd mention that.

[Bradley G]

If you are still coming this way, let's get together @ Byron for some runs & funs.
Thirteen states left?.... Get Busy! :D


I am driven! Seriously, I work on the road. My wife also does. In the past 2 weekends, I've driven from Huntsville Al to Rogkford Il and back, and from Huntsville to Marion IL and back. I do 75 miles a day here for work. When I want to go somewhere, I go. I've driven across the good ole USA (backroads) once. Did I mention I've done at least one documented burnout in 37 states? How about the fact I have more than 300 timeslips from legal drag raging. Yeah, I wouldn't sweat the mileage thing. BTW, I have an early build '03 with STOCK axles. Just thought I'd mention that.

[MENINBLK]

If you have NEVER replaced any of the O2 sensors
than I would say that would be a good place to start.
At 157,000 miles, they have done more than their fair share of work for you.

[JMan]

Paul,
Did cleaning the Airflow meter make any difference? That would be my guess. I'm thinking, by your reported mannerisms, that carbon build-up is not an issue! Do you have a way to read data from the PCM? You could look at the O2's and see if they're switching from rich to lean. Those codes (P0171 & P0174) are indicative of a loss of fuel control and not a faulty oxygen sensor. In fact as a general rule, you can't get those codes very easily with a faulty sensor. Also, if both codes are setting, there is likely a centralized problem (false air or vacuum leak, faulty or dirty MAF, clogged fuel filter et.al.) as opposed to two O2 sensors failing simultaneously.

Best luck,

J

[Paul T. Casey]

Paul,
Did cleaning the Airflow meter make any difference? That would be my guess. I'm thinking, by your reported mannerisms, that carbon build-up is not an issue! Do you have a way to read data from the PCM? You could look at the O2's and see if they're switching from rich to lean. Those codes (P0171 & P0174) are indicative of a loss of fuel control and not a faulty oxygen sensor. In fact as a general rule, you can't get those codes very easily with a faulty sensor. Also, if both codes are setting, there is likely a centralized problem (false air or vacuum leak, faulty or dirty MAF, clogged fuel filter et.al.) as opposed to two O2 sensors failing simultaneously.

Best luck,

J

I've got a scanner, and yes that's my thoughts (getting codes for both sensors). I've got different codes, front sensors stuck lean, front sensors lean off idle, at different times. The codes will stay off for anywhere from a few to several days. I also think I may have the carbon build up issue also, which is causing the ping off idle, and at the very top of WOT (5800 to 600 rpm). I'll look for leaks this weekend. BTW, the codes I've been getting are P2xx numbers, i. e. a 2 for the first digit, not a 0. Fuel filter is another idea, I'll check my records to see when I did it last.

[JMan]

I've got a scanner, and yes that's my thoughts (getting codes for both sensors). I've got different codes, front sensors stuck lean, front sensors lean off idle, at different times. The codes will stay off for anywhere from a few to several days. I also think I may have the carbon build up issue also, which is causing the ping off idle, and at the very top of WOT (5800 to 600 rpm). I'll look for leaks this weekend. BTW, the codes I've been getting are P2xx numbers, i. e. a 2 for the first digit, not a 0. Fuel filter is another idea, I'll check my records to see when I did it last.

Paul,
Try this-
http://www.motorcraftservice.com/vdirs/diagnostics/pdf/obdsm305.pdf

Go to page thirty and start reading. It's pretty intense engineering mumbo-jumbo, but it might help!

Good luck,

J

[Zack]

It is very possible your fuel pump is becoming lazy.

[superford3]

what are your fuel trims at

[Paul T. Casey]

Turns out to be an octane knock, although the CEL still comes on, as it's supposed to, and when it's supposed to (thanks again for the info Jman). I'm sure the O2's are ready for replacing again. Anyway, new gas seemed to make the ping go away. Car even ran decent on the track this weekend. Zack, not ignoring your advise either, I changed the fuel pump back in November after it failed. Thanks to all.