Thread: Another 16.4 post.

I know the response will be vac leak, but hear me out.

I took the car to the shop on monday to get it smoke tested. They could not find a leak. I sprayed everything I could. Even replaced some of the T's. Never affected idle.

Coolant/Oil levels are fine ever since my LIM change. But I had to replace a TB gasket cause I found a leak. Also, found one at the EGR block offplate, but I got it sealed now.

Since I can't find a leak after a thorough carb cleaner bath, what should I check next?

My LTFT's at 16.4 on idle on my "box tuned" pcm, however, when I scaled the MAF it gets/feels alot better. Only thing that looks bad is Decel...

Do you ONLY get 16.4 when you have a vac/exhaust leak? Or can it be attributed to other things... like adding headers...etc.

I have thoroughly read the 01+ fuel dump issue, and I have tried 98 files...etc with the same result.

Anyone in the Southeast wanna make some money before I put this thing in a ditch? LOL

Originally Posted by Lawngoose

Do you ONLY get 16.4 when you have a vac/exhaust leak? Or can it be attributed to other things... like adding headers...etc.

Leaky headers can do it, a screwy MAF and/or MAP could do it, and a bad tune of course could do it, a modified throttle body without compensating in the computer would do it, etc. Vac leaks are the most common reason, but not the only one.

I have pace****ters, that have been welded up. MAF has been replaced, I guess I could clean it. Still have the factory MAP (128k) on it. And the stock TB.

thanks for this post i spent forever looking for my vac leak and it was my LIM egr block off plate...now i just gotta get that shyt to seal....

Originally Posted by Scimmia

Leaky headers can do it, a screwy MAF and/or MAP could do it, and a bad tune of course could do it, a modified throttle body without compensating in the computer would do it, etc. Vac leaks are the most common reason, but not the only one.

wouldnt a bad map or maf throw a code???

Yes, but I think the MAF or MAP have their own specific codes...

They could once they get bad enough the computer knows that it's a false reading, but if the reading's just a little off, how would the computer know?

I guess I could throw a new MAP sensor in there. I mean ... i am rich... lol

I stuff a different tune on my car... and i am running better... but still have a stumble from 2-3 on part throttle.