At 90K miles, engine began having intermittent stutter under heavy engine load between 3-4K rpms. Problem progressively got worse until a check engine light came on indicating a P0303 code, misfire on cylinder three. Finally car left wife stranded when ALL warning lights came on and car went into limp mode.
First I took to local Honda dealer and wasted $150 on diagnostic and was told it needed valves adjusted and spark plugs changed. So, I gave a thorough visual inspection, adjusted valves, changed plugs, swapped coils and plugs around, cleaned throttle body, compression test each cylinder, problem still occurred. Checked fuel trims for lean or rich condition, all normal. Then, I took the intake manifold off and saw back of valve stems had a decent amount of carbon and oily buildup, but not enough for me to think that could be the issue. That was all but confirmed when I inspected each set of intake valves and cylinder 4 was WAY worse than 3.
Final repair was to replace all four injectors, do my best to clean the back of the valves, and add a catch can. Test drive seems all good now, but wife's lead foot will tell the tale. I'm going to run a can of GDI valve cleaner through there soon and see if that makes a noticeable difference in performance. Hopefully that'll clean all the carbon I couldn't get. 40K later, I traded it in for a new car, but didn't have any more issues. Good luck.
Beck Arnley injectors from Rock Auto.
Catch Can from Amazon.
Cleaner from CRC.
16 окт 2024