worse idol and hesitation after tune up

[wardak33]

hey gus. last weekend, i cleaned the throttle body and replaced the air filter. By doing this, i thought that i could get a better and smoother idol and some MPGs. i think i did get a slight increase in MPG's, but the idol is a lot rougher now. Just yesterday, i replaced the fuel filter. I haven't driven it enough to notice a difference. This weekend, i plan on changing the spark plugs (BOSCH double platinum) and see if that helps. Someone had suggested that i disconnect the battery for 10 minutes for the PCM to reset. Should I try that? someone else suggested that i change the PCV, but its really hard to find another valve, why is that? do TB's not have PCVs? any help would help. I will post a video of the start up and rough idle/hesitation shortly. THANKS!!

ps. car is at 125,000 miles....4.2L i6

[maxwedge]

Was it like this before you did the work? Any Cel, have you scanned it for pending codes? Lots of unanswered issues.

[wardak33]

Originally Posted by maxwedge

Was it like this before you did the work? Any Cel, have you scanned it for pending codes? Lots of unanswered issues.

check for those, no lights or pending codes. the hesitation was like this before, and the idle was rough..but not this rough. here is a video. you can't really see the rought idle, but the hesitation, yes. while i was taping it, i noticed a weird popping noise underneath while i was revving the engine. now i'm thinking it may have something to do with the exhaust system.

http://www.youtube.com/watch?v=6IQ99-ub4J4

[maxwedge]

I am on a phone line so this downloads 2 seconds at a time, the exhaust popping sounds like an internal engine problem, causing a misfire, I would do a full scan and look for misfire counts or pending codes, if it points to a certain cylinder, do a leak down test or compression test.

[wardak33]

Originally Posted by maxwedge

I am on a phone line so this downloads 2 seconds at a time, the exhaust popping sounds like an internal engine problem, causing a misfire, I would do a full scan and look for misfire counts or pending codes, if it points to a certain cylinder, do a leak down test or compression test.

i was afraid of that happening. but isn't there a possibility that a weak spark plug would be causing the popping noises? the popping noises occur only when the vehicle drops in rpm after revving the engine. for example, if i reve to 3000 RPM and let go of the gas, then the popping sounds occur until it is back to idle. also, i didn't see any pending codes when i checked for it a couple days ago. someone in a different forum suggested that the unburned fuel caused from a weak spark plug can also cause these noises...

[maxwedge]

Possible but , I misread your post, I thought you changed the plugs, when they are out look for one discolored, also just for convenience, do the compr. test. If this is the 1st set of plugs yes one could be bad or even a coil, usually that sets a code. Only a high line scanner will pick up misfire counts or pending codes. I would not use Bosch in this engine, stay with Delco plats or iridiums.