The CEL will stay on until a certain number of cycles. It will then turn off but the lean condition will remain.

 

Will the lean condition hurt anything?

 

good question.

 

"Running lean increases emissions, increases heat, usually increases fuel economy, reduces power and increases the chances of knocking."

http://ackthud.com/shawnfogg/mixture.htm

You may have trouble starting your car from a cold start also.

 

This is almost sounding like im not even gonna bother putting an intake on my SS. ahh

 

I can't honestly believe adding a CAI causes so much additional air to flow into the engine that it's actually leaning out. I think what's really happening (and I could be wrong ) is that the MAF is simply sensing more air entering the engine than previously did and having a **** fit because there seems to be very little margin for change when it comes to tolerances with this vehicle.

Hopefully this is the case and no one has any serious issues with their engines. I would hope if the 2.0L was built for F/I that a little additional air coming into the S/C isn't going to damage the vehicle in any way...I just hope I don't run into this when installing an intake on my 2.2.

Permafried-

 

I know im going to hold out for a while and see what happens. This is just to frequent for my taste buds.

 

If the car is running lean that means it is not running enough fuel for the amount of air entering the engine. I would think the problem is the MAF is not sensing all the air entering the new intake. If the intake is more free flowing than the stock intake, the air velocity will be lower, but air volume would be the same. With a lower air velocity the MAF is probably thinking there is less air entering the engine then there really is, so it only supplies enough fuel for the air it sensed. The lean condition is then noticed by the O2 sensors in the exhaust.

I could be wrong...I'm not a mechanic.

 

I think the PCM is confused. As I was erasing the CEL my buddy was noticing that the readings from both O2 sensors were reading very rich. The light has been out for 2 days now so maybe the PCM will adjust to the increased airflow. I still firmly believe that the MAF parameters are very tight and the intakes are not being accepted but I guess only time will tell. All the techs around my area tell me that the car is not running lean and don't sweat it until a new recal comes out.

 

well heres to hoping a reflash will actually fix the problem.

 

when my buddy scaned my car he said the computer was adding 19% fuel to the car. So I wouldn't be beating on the car untill this problem gets fixed.
Joe

 

what exactly does that mean? its adding an addition 19% fuel?

 

BINGO! This is what I was refering to in one of my posts in K+N installed pictures thread. The MAF is not picking up the true reading of the air entering the engine. It's sensing less, therefore the PCM is adding a given amount of fuel to that reading, then the O2 sensor is picking up the unused oxygen and detecting this as a lean condition. DTC p0171 sets, CEL turns on.
Yes, the tolerances for fuel control are very tight, for emissions compliance reasons. A CEL will illuminate any time the PCM detects a condition that will cause vehicle emissions to increase 1.5 times over mandated limits set by the EPA.
Chevrolet WILL NOT post a recall, reprogram for the PCM, or anything else to fix or solve a problem that we have created by a modification. They will only address issues that may arise from their engineering.
Notice most lean codes, p0171, are setting during or right after cruising; highway driving!? The system is designed to run on the lean side at this time, hence 30mpg. The fuel control limits are walking on a tight-rope at this point, any change will cause a loss of balance.

 

I wonder how the stage 1 reflash will react to the same conditions set by the intake.

 

This means the fuel trim value, do not confuse it with adding 19% more fuel, only GM knows the exact quantity/percent. Anyway, zero is center, (stociometric; 14.7:1 airfuel mixture). A positive % is that the PCM is adding fuel to the engine in relation to its programmed value, to sustain a 14.7:1 a/f mixture. A negative % is that the PCM is giving less fuel than programmed. The PCM will set a p0171 if the fuel trim value exeedes 18% for 2 minutes or more.

 

Modern Performance had the prototype for a while. I wonder if they had any trouble with the product.

 

That is a good question. I can tell you and everyone else this, I have reprogrammed my PCM with the latest software for an "Idle Quality Issue", I have also done this for a customer of mine with a SS/SC. He had a CEL with p0171, car is totally stock, I cleared his DTC, reset fuel trims (w/ Tech2), and reflashed PCM with latest software. As for my vehicle, I have a K+N conical filter w/lower airbox cover left off, reset fuel trims and reflash.( I know many have had CEL's with airbox mods or filter changes). Neither one of us have had any CEL's since. I drive 40 miles on the highway and have observed my fuel trims at this point, long term and short term both at around 4-6%.
I'm not saying this reflash is "THE"fix, but it is something I have seemed to have done different. It may be a step in the right direction.

 

I am having an issue with cold starts with an irregular idle. Do you recommend me taking it in for a update of latest software? I also thred a P0171 a few weeks ago but had it reset, it was never looked at more closely.

 

You probably just forgot to plug a connection back in.

 

Yes, take the car in and tell them about the Bulletin for idle quality. I can't promise this will fix the cold start-up issue, because I really did not notice a difference on mine, but lets see if it helps keep the cell out. Also, I would give you the doc # for the bulletin, but I'm out of work for an injury.(try driving with only your right hand).

 

Thanks appreciate it I'll mention it when I bring it in probably next week.

 

Your welcome, I may stop at my shop by then and I'll try getting the doc# for you.

 

Yeah, I was hoping so! Our welder is now having a problem fabricating the sensor mounts, which is NOT good. If they're not done exactly right, the CEL light might come on (as you all know, everything has to be PERFECT on this car). Stupid cobalts...why can't they be easy? lol

 

Installed my K&N last night. CEL didn't turn on last night (only drove about 20 miles), but did this morning on my way to work (15 miles). I didn't unplug the battery cause people on here and .com were saying that they didn't get a code doing it that way. Guess that doesn't matter.

How tight did you guys screw the MAF screws in?

Oldbenwa

 

I'm wondering if i pushed the filter too far down on the intake. it has a short neck, and i think pushed it passed that. that probably doesn't matter though, just grasping at straws. i'm gonna clean the maf and clean the filter and lightly re-oil, see if that works. if not then i guess i'm stuck until a reflash.