Question about changing air intake and PCM program...

[Fourth Horseman]

This may have been answered previously, so sorry for a repeat but I'm confused. Is it true that with a new filter assembly (like the K&N) and intake tube I'll need modifications to my PCM to adjust a/f ratios? Shouldn't the computer be able to handle that on it's own? I'm considering a K&N setup to go with my Metco carbon fiber tube, but I'm not thrilled with needing a dyno tune to make it all work right.

[tmac1337]

I had a Paul's High Perf. air box on my car for a couple of months. It ran very badly. Performance actually improved when I went back to stock.

[Directedby]

This may have been answered previously, so sorry for a repeat but I'm confused. Is it true that with a new filter assembly (like the K&N) and intake tube I'll need modifications to my PCM to adjust a/f ratios? Shouldn't the computer be able to handle that on it's own? I'm considering a K&N setup to go with my Metco carbon fiber tube, but I'm not thrilled with needing a dyno tune to make it all work right.

I put on JTL and the computer adjusted intake automatically. It runs great. I also have DR SCT Excalbrator which runs well with stock intake or after market.

[Fourth Horseman]

This is why I'm confused. It seems some folks have trouble, others don't. What's the answer? :confused:

[Directedby]

This is why I'm confused. It seems some folks have trouble, others don't. What's the answer? :confused:

You seem to have the same mods I have and I do love the JTL and I am sure the K&N is equally as good.

I suggest you try it - mast everyone here that has did not have a problem. If you do have a problem then sell it in the classifieds section.

Good Luck

[Smokie]

I installed the PHP air box, did it at Dennis new shop, had the A/F ratio checked before and after. After installing air box the A/F went to 11.6 at WOT, the car ran fine, but I knew that my gas mileage would suffer a bit, kinda like people with gears right ?

So I had Dennis adjust my A/F ratio to about 13:1, at WOT which is more desirable for a N/A car, I would have notice no difference in performance either way but at 11.6:1 my gas mileage would have suffered a bit, that's all.

[Fourth Horseman]

I installed the PHP air box, did it at Dennis new shop, had the A/F ratio checked before and after. After installing air box the A/F went to 11.6 at WOT, the car ran fine, but I knew that my gas mileage would suffer a bit, kinda like people with gears right ?

So I had Dennis adjust my A/F ratio to about 13:1, at WOT which is more desirable for a N/A car, I would have notice no difference in performance either way but at 11.6:1 my gas mileage would have suffered a bit, that's all.

Ok, so there's no threat of it running too lean and threatening the engine or anything? That sounds ok, then. Thanks for the feedback, guys.

[rayjay]

Ok, so there's no threat of it running too lean and threatening the engine or anything? That sounds ok, then. Thanks for the feedback, guys.
I've had just the opposite, runs too rich with the PHP airbox and Lidio chip. Really carboned up a set of plugs and gas mileage dropped off. Once/if spring arrives I'm planning on having a dyno tune to correct the AFM.

[MENINBLK]

This may have been answered previously, so sorry for a repeat but I'm confused. Is it true that with a new filter assembly (like the K&N) and intake tube I'll need modifications to my PCM to adjust a/f ratios? Shouldn't the computer be able to handle that on it's own? I'm considering a K&N setup to go with my Metco carbon fiber tube, but I'm not thrilled with needing a dyno tune to make it all work right.

Easiest way to reset the Airflow is to disconnect your battery overnight.
Start the engine the next day and let it sit and learn to idle until it completely warms up.
Then take it out driving for at least 15 minutes or more and you should be fine.
From that point on, the PCM will adjust whatever it needs, automatically while you are driving.

If you make any other changes, such as plugs, thermostat, exhaust, etc,
you may want to think of tuning the Marauder on a Dyno to trim the fuel settings.
This way all of these can be brought to their fullest potential.
Just the air filter/air box/intake tube by itself will make a difference,
but not a huge difference.