I have a 88 iroc that originally had a 305 but we put in a 350 and it still has the 305 prom and computer in it, with some accell 24 lb. injectors and i've added ram air through the fog lights and some headers, and took off the catalytic converter, and thats about it, but my car was running good, and then i decided to take the screens off my MAF sensor and it started running rich, and it won't ever rev over 4000 rpms no matter hoqw long i hold it in first gear, so anybody got any ideas what could be going on ? And the computers not setting off any trouble codes and i've checked the timing a dozen times over, any help would be greatly appreciated, thanks.

 

If your straight piping your exhaust...your losing a ton of power...

Why did you pull the Catalytic converter?! There's alot of your power right there gone. You need a new chip for your O2 sensor now, because it'll run rich and cause your car to have low power.

http://www.howstuffworks.com/catalytic-converter.htm

 

I Am having a problem similar.. I dont know if i'm running rich, but i start to back fire at running temperture. it will take off real good until it hits around 160*. Then when i go to take off, pop, pop, and it sounds in the aircleaner... Heres what i think could be the problem... First of all i dont have a cat either.. second, When i put my exaust manifolds back on(after changing head gaskets) I couldnt tighten all of the manifold bolts all the way.. actually i dont think one of the four is even in started in the hole..
does anyone think by changing the manifolds to headers, and installing a cat as well will stop the backfireing(after putting in a new o2 sensor as well)???I'm savig as I type for headers but if anyone thinks this wont help, then i'll buy something else. thanx for any help

 

It was running rich even before i pulled the cat, i just had to buy a new MAF sensor, and i left it alone for a while then i pulled the screens, and it started running rich again, but i've read everywhere that pulling the screens shoudln't do anything, but i've talked to some mechanics around here and they all said pulling the screens was a bad idea, and i have a new oxygen sensor, only about a month old maybe, so what else could cause it to run rich, and will it running rich make it stop at 4000 rpms?

 

Since i still have a stock 305 chip in it, u think i shoudl get a stock 350 chip? will that maybe help too? Just an idea

 

Well, I'd definately look into a new chip. Your current chip is set for specific O2 mixture and such. Other than that, if your pulling the screens and it's running rich, leave them on until you can pinpoint where exactly the fault is occuring at.

On the question by TransAmTBI, it's either running too rich from the manifold opening.. does the manifold seem like it's cockeyed, covering part of the opening?

If it is, get a new one, that could be part of the problem.


Rsparhawk: chekc this out, maybe it'll give some insight-

http://www.tonnocover.com/Products/SuperChips.asp

You too TransAmTBI

 

Perform an archive search using the terms GUTTED MAF + RICH + LEAN and you might discover that you are not the only one to suffer this fate. Depending on the arrangement of the intake ductwork, you might be creating a false MAF reading.

For example:

• https://www.thirdgen.org/techbb2/sho...threadid=32557
  
• https://www.thirdgen.org/techbb2/sho...threadid=43084
  
• https://www.thirdgen.org/techbb2/sho...threadid=19512