Rep Power: 0

Hi everyone - First time thread poster, long time reader, LOVE the show.

Here's the deal: I have a '97 Civic HX (D16y5) that has had a long history of EGR system clogging and low EGR valve lift. I believe that the car still has these problems, but they have never really caused much of an issue before, so they persist.

Recently my Civic began to exhibit a weird problem where the engine RPMs warble at medium load. I can idle fine and I can rev the engine to high RPM without problem. It's the medium load condition where I run into issues. When at medium load, the engine revs up from around 1600 but then cuts out at around 2,200, then does it all over again, repeatedly.

I pulled a few CEL engine codes: P0130, 131, 132 (engine misfires on cyl 1, 2 and 3), I'm also getting that error code for the low EGR valve lift (P01431 I think) and I'm also getting some O2 codes. I'm not all that worried about the O2 codes because I suspect that whatever is causing the engine warble condition is also causing me to have a poor combustion (and therefore improper air/fuel ratio).

Has anyone encountered this before? Any possible theories about what may be at play here?

Thanks for your help!

 
Rep Power: 812

possibly the egr valve is fine and its the passages in the engine that are clogged.

 
Rep Power: 200

check spark plug and wires
engine misfire means ur plugs r not igniting the gas in the combustion chamber