Hi all, I've been a long time looker, first time poster on the forums. I've been searching to see if anyone else has had this problem. Firstly, I drive a 2001 GMC Sierra with a 4.8L.

Problem: While accelerating I notice a little bit of boggy-ness and not a lot of pickup. When I take my foot off the gas pedal, the RPM's hang at about 1.5k to 2k (depends on what speed I'm decelerating from) and I get a nice vibration and what sounds like the engine is trying to match the speed of the trans, and only goes away when I'm back in a full stop. No error codes are being thrown so I'm kind of clueless as to what I need to check first.

Now, I just installed a Spectre 9900 cold air intake, put new Bosch Platinum 2 plugs in (after reading reviews on them, shoulda went with AC Delco's ), added 2 bottles of Seafoam to the gas tank and cleaned the throttle body. It wasn't until I filled up with premium, more seafoam and it just so happened to be rainy/windy this whole week when I noticed the problem.

I'm not sure if it's the TPS, IAC, or Crank Sensor, Vacuum Leak, PCV Valve or what. I know it's not a linkage problem, MAF problem or sticky butterfly in the TB. I just don't want to take it to a mechanic unless I absolutely need too. Currently trying to reset my computer via unplugging the battery to see if that can reset the sensors.

Thanks!