So I have a 2017 GT 6R80 that I’ve owned since new. In May 2021, I had a VMP Gen2 installed at 29k miles, and took it to the local 1/8th a few times. At one point in 2021, I put Octanium in it to run the 93+booster tune from PBD, but I couldn’t get my pos SCT X4 handheld to upload the tune, so I eventually gave up and went home and just cruised with the Octanium mixed in.
That was the last time I had it at the track and I’ve mostly baby’d the car just driving 20 miles to work and back a few days a week since 2021. Around October 2022 and 8k miles after the install, the dreaded P0308 code popped up and I parked it. Finally got around to taking it to the same shop in February 2023, and they did a compression test which all cylinders came back between 178psi to 185psi. So they said the plugs looked a little dirty, possibly from that octane booster I ran before, and replaced them with a fresh set of NGK 6510s. The code never came back for the rest of the year and the car had no problems.
Today, while cruising to the grocery store, never getting above 3000rpms, P0308 came back on. Also showed the P0316 misfire on startup code. Is it possible that the new spark plugs are already dirty again? Or should I be looking into having cylinder 8 inspected more thoroughly this time? Now I have quit driving the car often at all lately, maybe only putting 100 miles on it a month or longer so it does have older gas in it. There’s really nothing special about the setup though, just running a 79mm pulley on 93 and the car ran 6.70@106mph in the 1/8th, so hopefully I haven’t already done damage to the engine
That was the last time I had it at the track and I’ve mostly baby’d the car just driving 20 miles to work and back a few days a week since 2021. Around October 2022 and 8k miles after the install, the dreaded P0308 code popped up and I parked it. Finally got around to taking it to the same shop in February 2023, and they did a compression test which all cylinders came back between 178psi to 185psi. So they said the plugs looked a little dirty, possibly from that octane booster I ran before, and replaced them with a fresh set of NGK 6510s. The code never came back for the rest of the year and the car had no problems.
Today, while cruising to the grocery store, never getting above 3000rpms, P0308 came back on. Also showed the P0316 misfire on startup code. Is it possible that the new spark plugs are already dirty again? Or should I be looking into having cylinder 8 inspected more thoroughly this time? Now I have quit driving the car often at all lately, maybe only putting 100 miles on it a month or longer so it does have older gas in it. There’s really nothing special about the setup though, just running a 79mm pulley on 93 and the car ran 6.70@106mph in the 1/8th, so hopefully I haven’t already done damage to the engine
