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I've got a 2016 981 Cayman base 2.7 manual 35k miles a couple month ago. Long story short, I have irregular misfire (mostly in cylinder 1, 2, and 4, but on all cylinder occasionally), No CODE at all. Could feel the dead spot under constant acceleration. Live stream data shows random misfire comes and goes among all cylinder. -New battery replaced -New Spark plugs and coils -New genuine air filter -Belt condition and tension checked (No problem) -Throttle body cleaned and checked (No problem) -MAP sensor replaced, (Covered with oil, no white smoke when start the car, intake manifold had a bit of oil in it so I replaced AOS) -AOS replaced (Diaphragm inside old AOS was fine, but there was an evidence of leak to outside)
But there was an excessive vacuum (my assumption), when I am trying to open up the oil cap, it as a bit hard. Also, I could smell fuel inside the cabin and front area of the car now, after the AOS got replaced. Coincident? I noticed the cabin is sourcing the air from where right behind the fuel canister. Can fuel canister or fuel vapor purge valve causing a vacuum problem as well? how about crankcase vent valve? I am so lost.
Fuel smell inside the cabin while driving (when stop) after AOS replacement is very suspicious to me, but not sure what can cause that. Pipes are all connected. Double checked. Please help guys. Thank you!
Last edited by crosewing981; 08-11-2024 at 06:04 PM.
08-11-2024 | 05:09 PM
Vacuum related random misfire (Not AOS problem)
