98 XLT 4.0 SOHC Cold air intake issues...

[davew_]

I recently had put on an intake and as soon as the install was complete the engine idles a little bit low and the truck seems to be a little bit sluggish under slight acceleration. When I full throttle it, it still takes off ok but still a little rough. The truck ran fine before this and the 02 sensor in the rear on bank 1 has the occasional light, but as far as I know that one shouln't affect performance and never has in the past. I've checked the MAF is facing the correct way and is plugged in, and that the air temp sensor is actually in the tube and also plugged in. The two other vacuum lines into the intake have breathers on them and the overall intake itself is attached solid with no loose connections.

I was wondering if anyone else has ran into this issue after doing an install for an intake. I have put on many intakes in the past with friends and never had an issue like this so im a little baffled. Any help would be greatly appreciated. Thanks!

 

[Sedition]

I'm gonna suggest a vacuum leak somewhere. Now, because you're getting an O2 code on only one bank I think that the intake plenum gasket may be leaking in a way so that only one bank is receiving too much air.

Is it the same when the engine is warm and cold?

 

[davew_]

It is the same both when it is cold and it is hot. The 02 sensor issue is i think unrelated to the current sputtering issue but is def something to look at. this happened as soon as i put the intake on and before that the truck ran fine. There are a few small exhaust leaks as well but that is gonna be addressed soon.

 

[2000StreetRod]

unmetered air

. . . The two other vacuum lines into the intake have breathers on them and the overall intake itself is attached solid with no loose connections. . .

All intake air must go thru the MAF sensor to be measured. Otherwise, the air/fuel ratio will be lean.

 

[davew_]

Update... I removed the engine side piece of the aftermarket intake that the MAF and airflow sensor and the 2 vacuum tubes attaches to and reinstalled the factory tube. I did this because the vacuum was acting funny with the aftermarket tube. I left the adapter and cone filter after the MAF so it still has a nice little growl and it drives fine now.