Added Fuel Injector Cleaner & after 15 minutes have CEL

[resolute]

Anyone experience getting a CEL (Check Engine Light) after adding Fuel Injector Cleaner to the fuel tank. I put in a bottle of STP GDI fuel injector cleaner and filled up with 94 Octane Chevron Sumpreme. The bottle says it treats up to 80l of Gas (21 gal) and I put 3/4 tank (@55l - 15gal) - drove for 15 minutes (rather aggressively - 5K RPM shifts) and then a CEL light came on. Its a 13 A6 3.0T with 55,000km (34k Miles). Normally use 91 oct (shell or esso). I've never added anything to the fuel since I bought it last year with 45,000km on it... just used Tier1 gas premium. I don't have a VCDS to check. If the car is not experiencing any issues - should I worry or just ignore?

At the same time, since I don't have a VCDS - I'm thinking about OBDEleven or that New Ross-tech one - Is there a point to spending more money with the Ross-Tech one? Or will I get what I need with the OBDEleven? I want to do some mod's and check when shit like this happens.

Thanks

[Slickn]

I've used techron fuel treatment before with no issues... but im running the latest audi ecm software. It's quite possible that you are throwing a catalytic converter efficiency code if you aren't on the latest software. Only way to know for sure is to get the codes read.

[tenspeed]

Make sure your fuel filler cap is on correctly.

[JoeCaMotto]

Make sure your fuel filler cap is on correctly.

+1 the filler cap is quite sensitive on Audis

[Roadwarrior]

yep...filler cap. Bet money on it.

[resolute]

Tried the filler cap - it was on correctly. I took it off, waited about 30 seconds, then closed it again, started the car, drove for about 20 minutes - and still light on. Now - if it was something stupid like the filler cap - would the light by itself go out if corrected? or since that tripped - do I need to go to the dealer to have them reset it? Nothing is sounding off in the engine - its smooth as silk. The oil level is fine - although I really need to get a real dip stick - not too trusting of the electronic ones.

Regarding the catalytic converter - i've heard about that - will have to check if the car had that taken care of during last service, which co-incidentally was the last one under Audi care and the car under warranty.

[Roadwarrior]

most shops can reset that error if filler cap was issue.

[resolute]

Thanks for the input.... well it was not the fuel cap. The error was Fuel too rich in Bank 1. Interestingly enough.... all was good with the car, until I was stuck in stop-and-go nowhere traffic for 30 minutes - essentially the car was just idling. As soon as the traffic started clearing up, and I pushed the accelerator, the car sputtered and I pulled off to the side of the road, shut the engine, waited 5 minutes and started it up (not sure what to expect). it seemed to correct itself, however, to avoid an accident 10 minutes later - I had to floor it - and poof... big cloud of grey exhaust smoke.. so i figured she needs a good cleaning. I then proceeded to go for a 3-hour drive with WOT as much as possible -- starting gently - but pushing the revs higher and higher, so that eventually I got to near 6000 before shifting. I suspect this was some buildup (carbon or whatnot) from being very gentle with it all winter. About 1/2 way into my drive the CEL light shut off... and now everything seems to be hunky dory.