Spark plug Bosch or Champion

I’ve been running champion plugs for about 40k mi without issue.

changed out the spark plugs, all except for cyl 1 had crazy looking plugs. Used Bosch platinum 6704 cleared up the CEL and also the stability and TC lights no longer flash so somehow that was connected I guess.

For iridium spark plug. Do NOT gap them. I have bosch double iridium spark plugs and over 120K miles now. Still goes strong.

My car has Bosch Double Iridium spark plugs. Over 120K miles now still go strong.

I'm still not entirely convinced that it is weak or under ignition versus over fueling. Either way it just seems like it's having a hard time burning the fuel that it is getting. I still can't help but wonder about the Bosch Platinum 2s. I have had good luck with them before my Mark 2 GTI and the car did run well with them for a good 10 days before all of this started.

I have measured resistance above 5k and determined the plug to be causing a problem. Typical resistance is 1-3 kOhm, sometimes less for a new one.

My 2000 with California emissions (regular cat and then two pre-Cats at the exhaust headers) would only run properly with the oem spec NGKs. Threw Bosch in their once and it ran terribly.

Ever since Bosch moved spark plug production to Russia, the quality has been sketchy.

Champion spark plugs are rubbish, not sure why they’re even sold.

I quit buying Champions 40 years ago for shitty quality.