I just added L/T headers and Magnaflow high flow cats. I am now detecting a slight miss when the truck is cold. At very light throttle/low rpm I am getting a miss for about the first 1/8 mile of driving. As soon as it warms up it clears right up. Anyone else notice this? Is it just taking longer for the O2 sensors to heat up? It feels like it is loaded up then clears out and runs great.

 

My 'cold' BR7EF plugs always do that, even when the eng is up to temp(at low rpms). I don't have the L/Ts so I'm not sure what your problem is...........

Dan

 

I haven't experienced anything like that since installing the LT's. Sounds like maybe its in the plugs

 

Currently running Denso IT-20. Never missed a beat before the L/T install. No other mods done.

 

Those are the same exact plugs Iam running

 

Maybe it is a slight exhaust leak. I have had exhaust leaks on other cars that were noticable only when everything was cold.

 

For sure not a leak. Can't hear, I feel it stumble slightly then clear up. Happens just above idle. If I get into a little more it clears up.

 

You may have to clean your IAC, I just cleaned mine


Thats Alcohol NOT WATER I'm CLEANING WITH


I'd show you more pictures of how much crap came out,
BUT I CANT GET INTO MY GALLERY FOR THE LAST WEEK

 

I've got the exact same stumble... been trying to rid of it. Let me know if you find a smoking gun.

Coldie

 

I will check the IAC tonight. Weird that it started with the L/T install. Brake/carb cleaner ok to clean the IAC?

 

Yes, any solvent is ok. I've cleaned several of them on various vehicles.

Dan

 

I cleaned the IAC last night. Not real dirty. A few small carbon deposites on the plunger. No miss this morning. Perhaps it was just enough. Keep you posted if the miss is gone for good. I used carb and choke cleaner to hose it out.

 

Hope that does thank care of the stumble. Its nice when the solution is cheap and easy