Survivor058

iTrader: (1)

so what do we do if the CEL is bc of the rear o2 ive been drivin around like that for a while and now its inspection time and the car wont pass with the CEL on so any help would be good i have a CA 2.5 DP

update i went out to check my fuses ........................*Pops hood* *waits for smoke to clear* lol ..............opens fuse box and reads for correct fuse *pulls fuse out and holds it up to the light* prays!!! and!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ITS NOT BLOWN dammit so back to the drawing board the only quick fix i can think of for the moment is to clear the code literally 2 seconds before it goes in for inspection

Otown07

Anyone have any trouble with a fresh (and dealer installed) Stage 2 throwing a code? I got a CEL about 30 miles after getting it back from the dealer. The guy at Discount Auto checked the code and said it was running lean, which is the part I don't get. My powertrain is stock short of the Stage 2. And Stage 2 is supposed to clear up the lean running issues that can come up in stock trim, right?

Halfcent

If it was dealer installed, its dealer warranteed. Bring it back.

Otown07

That's what I did this morning. I was just looking for a hint before I had a chance to take it back. Turns out a broken o-ring on the #1 injector was letting a little air in.

Fresh

i'm new to the modding world and have a few questions pertaining to the P0171 code that my 06 SS/SC is now throwing after installing a JBody Performance Vortex 3" CAI. The CEL has been on for a few weeks now; it's a steady lit CEL. I had it scanned and cleared once already but the next day it came back on and has been on ever since. I know in the first post it was said that this shouldn't harm anything...except in my case it harms peace of mind. I would really like to have this fixed so that the CEL disappears so that in the future if I were to throw a different code for any reason then I'll know for sure that something is wrong instead of just thinking that it is still the P0171 code.

I was told to get the data logs of the fuel trim and get the MAF recalibrated. Before I do that though I plan on removing the tire and takeing a look at the intake to see if the MAF is ok and to make sure that the sleeves are still fastened tightly to the piping. The vacuum hoses I know for a fact are fine.

I also know that this could be caused to a malfuntioning fuel injector, but in this case I don't believe it is since the CEL only came on after the day after the CAI was installed. But, I notice a lag in 3rd and 4th gears when I'm really jumping on the gas at around the 3500 to 4000 RPM range where the car acts like it doesn't get enough gas or air or something.

Does anybody have any suggestions?

Halfcent

When troubleshooting a problem, the saying is "look where the light shines best". So you are right, if the CEL came on right after putting on your intake, then it's probably your intake. The easy way to verify that is to put your stock unit back on and clear the code to see if it comes back.

This code along with your new intake would lead one to think you have a leak in that intake. So check all your fittings and attachments to make sure its snug. And check to make sure you didn't but the MAF in backwards, because that will cause it too.

outtamymind

also for the P0171 code there is a bulletin on that code to get an injector test done and if any of the injectors are running lean then all 4 injectors are to be replaced and a new calibration be installed to the ECM. but as halfcent said this code can also be thrown due to an air leak on an aftermarket CAI. so double check all those lines and get the code cleared. if it comes back on again then i would recommend getting it booked into your local dealership to have this service performed. and if anyone needs it i can post the bulletin. i've posted it in a few other threads already.

Fresh

Thank you for your input. I know for a fact that the MAF isn't in wrong or so i think. The reason being is that when I first installed the CAI I did have it in backwards and when I started the car up for the first time it sputtered horribly bad and would shut off after maybe 30 seconds. I battled with it for awhile before it had dawned on me that the MAF could have been in backwards which it was. Once I got it in the right directon it started right up and had no problems until the next day when the light came on.

I still may take her in to get dyno tuned especially since I have a new magnaflow cat-back to install as well.

68nova200

iTrader: (2)

thanks for the write-up

YellowLT

Im Running Lean Bank 1 and one for Catalytic Efficiently. But I Killed my Kitty.

Fresh

i have read that bulletin in full length. i don't believe it to be due to a failed injector only because the light came on after installing the cai. it can't be ruled out completely though. it's in the back of my mind for now.

about the dealership, i called there the other day and talked to a service guy and he said they couldn't or wouldn't do a reflash on the ECM or MAF because the intake is after market...
btw my warranty is expired.

outtamymind

ya if im not mistaken for the bulletin to be in affect then you would have to be under warranty. but keep in mind if you have a leak in your intake system then you throw off your fuel to air mixture for the combustion chamber causing either a lean or rich condition. for the p0171 its a lean condition. so thats where double checking and tightening your connections (tightening them until you can't tighten them anymore) comes into play before you waste a techs time for something that you could have done.

Witt

The guy that told you to get a log of your fuel trims and have the MAF recalibrated is probably completely correct.

What a lot of people don't understand about aftermarket intake pipes is that they change the diameter of the housing in which the MAF is located in. On a Cobalt, MAF calibrations are a bit off as it is for some reason. GM released a fix for this for a few different trim levels, I'm not sure which though.

When intake pipe diameter increases, more air is ingested into the engine without the MAF knowing the pipe size has increased. Increased airmass is effectly passing by the MAF unmetered now since the MAF does nothing more than sample a percentage of incoming airmass. With the diameter increase, the MAF sample percentage now decreases allowing additional airflow by unmetered.

When the o2 reads the afr results in closed loop, thats where your trim correction comes into play. Exceed the correction by 20% or so and your p0171 or p0172 sets. Since the stock calibration can be up to 19% off without setting a light, any little change can cause the check engine light to come on. On custom calibration, I shoot for a +- 3% error on a MAF calibration. However thats a custom calibration, not an intended canned tune like GMs stock calibration. Thats why some cars are more prone to the code than others.

Fresh

The above bold statement came straight from Brian at Intense. I will triple check all connections and hoses to make sure everything is super snug. Another question, let's say i discover that one of the clamps is loose and the piping came out of the sleeve just a little bit and is letting in or losing air through that crack and I were to remedy that by pushing the pipe back into the sleeve and tightening the clamp down. Will the code disappear by itself after driving for 20 or 30 miles, or will I have to have it cleared and wait to see if it comes back on?

Witt

It will need 3 warm up cycles without the fault setting again iirc.

outtamymind

what witt said.

Fresh

3 warm up cycles? what's that? a trip around the block 3 times? lol

outtamymind

no starting the car. driving it for a while. shutting it off. and doing that 3 times. you will usually go through 3 cycles in a weekend. or depending on your day to day life in a day

Fresh

yeah i drive 1.5 to 1.75 hrs in the morning to get to work and 2hrs to get home. plus i drive to get lunch sometimes.


so what you're saying is that if i were to find something wrong with the intake and fixed it and drove around for 3 cycles that the light should turn off on it's own on the 4th cycle?

outtamymind

should yes. unless the condition is set again. then it will stay illuminated. if you really want to be sure tighten everything up and then go to your dealer or an auto parts store or someone with the ability to clear codes and clear it manually then if it comes on again then it is something else. did you clean your maf sensor when you installed your CAI

Fresh

sounds like a good suggestion. no i did not clean the MAF. what type of cleaner can I use on it?

outtamymind

brake clean should be fine, i can't remember if carb cleaner will harm it or not. or you could go the safe way and try just using compressed air to try and blow it clean.

Fresh

well i got some compressed air and brake clean so we'll start with that. i wish it would get warm out cuz working in ice and snow in the drive way really blows a big one.

does anyone know of anybody in the Pittsburgh area with access to any of the following: HP Tuners, GM Tec 2 Service Tool, or an Aeroforce Scan Gauge? I plan on buying a aeroforce scan gauge at some point but not until after this all gets resolved since i do not have the money to do it all an once.

any idea where Intense-racing is located in Ohio? their website is blocked here where i work.

how much is a dyno tune approximately?

outtamymind

ya i would try the compressed air first. and my brother had used our shop brake clean to clean his now i don't know if the stuff thats in the spray can is differen't then our bulk stuff so i hold no responsibility if anything were to get screwy

Fresh

wow you're lucky you made that statement cuz i was holding you responsible for any damage that i do to my car haha. air duster first, you got it!