ghost_masterCL

Recently i've noticed a pretty big power loss at low RPM when i'm giving it more than 50% throttle.

For example, going 25-30 mph rounding a corner, give it some gas, it downshifts to second gear, and gets louder but doesn't really accelerate any faster, it shudders a little bit like it's either not getting gas or spark, then once it gets to a little under 3000 rpm it goes back to normal.

No CEL or any dash lights at all. Possibly unrelated, but sometimes while parked the engine revs on it's own. Usually only happens after a long drive. I can usually turn the engine off then back on and the revving goes away. I know the revving could be the IACV, but what about the power loss?

I know the power loss could be maybe fuel pump and/or filter, but you would think it would struggle at higher rpms if that were the case, and I don't want to just blindly replace stuff in an attempt to fix it. I was hoping for a way to maybe narrow it down.

Thanks in advance for any help.

ghost_masterCL

Update: it's not just low throttle situations now. got my oil changed a couple days ago, and afterwards was passing someone on the highway. At about 5k rpms I heard a loud pop that sounded almost like a backfire, but sounded like it came from the engine bay (uh oh.) The flex pipe on my header downpipe is torn, but only slightly. Not sure if it's an actual leak.

then the next day I was trying to reproduce the problem on my way home from work and did, and i got a CEL, YAY, now i can narrow it down.

codes were for misfires on cyl 2, 4, and 5. Multiple random misfire, and p1399 Manufacturer control Ignition system OR Misfire.

Going to work on it on thursday. Test plugs, wires, compression on each cylinder, egr, coil, and go from there.

saiko_cl_duck

how did you do?

I got the same problem as you. I changed out the plugs and wires, and put some fuel injector cleaner in it. Stopped misfiring.

Then my car was idling funny, so I had to clean out the IACV and the EGR ports, plus I cleaned out the intake plenum and the TB. Worked pretty well, except for the IACV, I had to replace it, still sticking. Not bad though, only 90 bucks at autozone.

Good luck

ghost_masterCL

It was the EGR combined with old spark plugs. The plugs were old so when the EGR was malfunctioning it got hot as shit in the cylinders which pretty much destroyed what was left of the plugs. Replaced the EGR which fixed the CEL, then replaced the plugs which fixed any remaining misfires.

peters_sweet_CL

I thought I was being crazy, but apparently its happened to others...this has happened to me a few times when i hit the gas, it downshifts and the car shudders but doesnt go much faster...in one instance, i turned the car off and started it again and it started like it was really struggling...the car starts/drives ok now. I dont know if im crazy but i feel like its not as powerful and it seems like my MPG is not as good as it was...my point is, theres no CEL or any kind of indication that somethings wrong...what can i look at/change without going to the dealer?

vegat59

any of yaw got some tips for me on getting the IACV out and cleaning it?