hows it goin guys im not really new to this forum just forgot my old username and password its been awhile since i been on here... but like everyone else i got some issues with my car ive been haunted by the engine power reduced for over a year now and for some reason dealers cant figure it out they have replaced a few things i hear alot of ppl talking about the tb being bad or the pcm im leaning more towards the pcm in my case just a few days ago the engine power reduced has been gettin alot worse its so freakin bad that before i even start the car im already getting the message just with key on and to top it off i was letting it warm up the other day and about 3mins it started missing horribly shut car off for a few mins and try one more time same thing starts missing horribly after a few mins then engine power reduce. we pulled all the codes p0171, p0507, p2135, p1516, p1681 and p2a01 tell me what u guys think i dont want to start buying a crap load of parts and have the same outcome oh and it seems to go into limp mode alot more often when its cooler outside specially in the winter. srry for the spelling im at work trying to be sneaky lol mod wise my cars is on a gm stage 2 tune car has 2.9 pulley custom cold air, mid lenth header, full 3in exhaust no cat or resinator ported tb and supercharger inlet thanks for any help in advance

 

That seems like a lot of mods to still be running the stage 2 tune. Get a custom tune, be it HP or whoever. (Though we have a wicked good HP tuner in Chicago, PM me if you want his info, he's not on this forum anymore.)

Are you sure it was misfiring? Because you didn't throw any of the misfire codes...

P0171 Fuel Trim System Lean ECM, PCM
P0507 Idle Speed High ECM, PCM
P2135 Throttle Position (TP) Sensor 1-2 Correlation ECM, PCM
P1516 Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance- ECM, PCM
P1681 Control Module Throttle Position (TP) System Performance PCM
P2A01 HO2S Circuit Sensor 2 ECM

 

it was missfiring horribly so hard to explain it was like it was on a 2 step at idel
ive had the car for almost 4 years i think the cars been to the dealer more then its been on the street this past year lol when i first got it great runnin car

 

your problem lies within a bad accelerator pedal or a bad throttle body. basically what those codes mean is that the input from the pedal and the throttle body % do not match. by any chance did this happen after you ported the throttle body?

 

engine power reduced has been comin on long before we ported the tb but the missfire did come after porting the tb

 

i'm almost positive that it's the accelerator pedal. i have seen another car with this issues. but i wouldn't feel comfortable with that throttle body either

 

now is it actually the whole pedal assy itself or is there a sensor u can change on it?

 

the entire pedal assembly. after working on a friends car putting a turbo kit on it. the car would idle at 1,200rpm and when you would hit the throttle it would immediately go into engine power reduced

 

another prob ive been having is high idel wich came after the porting idels anywhere between 1200 to 2000rpm and sometimes it idles fine also if u turn the a/c on it idles fine lol and sometimes i dont even have to start the car to get engine power reduced like this morning go to start the car put the key in the on position ding ding engine power reduced i hate computers lol i ended up driving to work with a car thats equavalent to a freakin riding lawn mower im dreading the ride home

 

i agree ^^ - back in spring when i put my new engine in it was misting when i pulled my wiring harness...when i got the new engine in it came up with a ton of throttle body codes and ECM codes and limp mode...i unplugged my TB harness and it was corroded to S**t, sprayed some contact cleaner and a green scrub brush and it all went away

just an idea to try

 

man ive cleaned every sensor i can get my hands on also bought some tb cleaner and cleaned that what i dont get is y its missing real bad all of a sudden does it just about everyday if u let the car idle long enough i dunno anyone got a part number for the pedal assy from partsdirect?

 

It turned out to be the throttle body thanks for the help tho bud by the way u converted ur car over to turbo correct?

 

yes i did

 

Nive how do u like it? Im on the fence with goin tirbo as we speak dunno if i should just peice it together for a lil cheaper or get zzps full kit? Any suggestions

 

I just had this issue resolved at the dealer! they replace the TB, the gas pedal assembly, the TB wiring harness, the pedal wiring harness, and wiring in the engine bay. NOTHING fixed what was wrong until the changed the computer. They put a new computer in my car and it fixed all of the issues I was having. I was getting the codes P2135, P2183, P1516, and one or two more (i don't remember exactly what they were though). This is not a thread by me but I was posting in it a lot:

https://www.cobaltss.net/forums/prob...-p0121-256367/

NEVERMIND, I just read through the whole thread and saw your problem is fixed, sorry lol

 

No problem thanks for the reply tho

 

i love it man. and to be honest, i did a half zzp/half custom kit. if i were to do it again, zzp all the way. you can't beat the fit and finish of it all

 

its not alot of mods to be running stg2

 

Zzp is a pain in the ass to get ahold of but thats what i planned on doin half zzp and half custom id love to see the balt put down 400 to the tire lol now i hear alot of mixed answers on this how reliable is 400hp on a balt? Thats kinda my goal is to hit that mark with the car

 

replace your TB, 3 codes in there are what i had for when my tb took a poop. a tune is recommended seeming the tune is made for having a CAT. that being said aren't gm s2 already made to run pig rich? either way get a damn tune lol even if its from zzp. zzp has the most stable reflash i seen around