Please hear me out. I got brand new NGK spark plugs @ 173k and 6 new ignition coils @ 183K after getting P0106 (MAP) and P0302 (Eng. misfire cyl 2) error codes in Nov 2023 (10 months ago). The codes kept coming back despite MAP Sensor cleaning, throttle bodies cleaning, vacuum leak check, and troubleshooting/swapping of the spark plugs and coils. During one troubleshooting session we found one very small trace of oil in 1 spark plug but nothing outrageous that could point to an obvious leak... car was still very drivable (not critical fix) so I took my time, but my next steps would have been to order a new MAP Sensor, replace all related gaskets (never replaced so could be old/worn out), replace all vacuum/hosing. Then came 2 more codes one day for the O2 sensors (P0132 and P0152) which the mechanic pre-warned me about using his code scanner, along with my fuel gauge not reporting my fuel amounts correctly.

I finally had time this past Aug to start shopping for new parts including the new O2 codes but all of a sudden the error codes disappeared on their own one day in early August. Before that, the P0106 and P0302 codes had actually disappeared in mid-June. So in 2 separate instances, P0106 and P0302 codes disappeared and then the O2 codes disappeared.

Is this normal? Has anyone experienced this before? Constant error codes for 6-8 months and then Month 9 and 10 they disappear on their own? With 0 interference from me and my mechanic. Slightly relieved, but I am baffled and more skeptical than ever so I've purchased a code scanner to check once in a while to see if I'm getting fooled. The car is 12y old and sitting @ 192k KMs and I want to drive it until I can't anymore.