Check Engine Light E46 '04 M3

[frw73]

Hey guys. I just installed a Carbonio Cold Air Intake last week (ignore the GruppeM on the sig - was taking too long to get this order, so I got the Carbonio one instead on the advice of M3Motorwerks' Zack). As in the instruction manual, I let the car idle for 5-10 minutes, and at no time did the check engine light illuminate.

Anyway, car was running great at the time. Just before the install, I filled my gas tank with 91 Octane gas at a station I usually don't go to but had to in this situation because I was in dire need of fuel.

Now, one week later, the Check Engine light comes on solid yellow and stays on.
This happened less than one day after I re-filled my gas tank with 94 octane gas (which usually goes into my car, but I had to refill at the '91 station).

Car sounds fine, engine note at all RPMs is no different than it was one week ago after installation of the CAI, and there are no real 'symptoms' other than the Check Engine Light

I have read through all the SEARCH pages on this forum. I have around 9,000kms on the car. I have checked all electrical connections including the mass airflow sensor, and all hose clamps, tubing, etc under the hood including everything to, in between, and from, the new cold air intake. I have checked the gas cap and ensured that it was on properly. I even disconnected and reconnected the connector to the mass airflow sensor, and then idled the car again for 5-10 minutes thinking that this perhaps was the problem.

I have heard other people talk about a change in gas perhaps causing the problem, and a loose or faulty gas cap as the cause. I have tried to solve these already (one post recommended using Vaseline around the rim of the cap before putting it back in place, and I have to admit, that I didn't really want to do this.... should I? I haven't abused the cap, it's not stripped, and still positively locks with a 'click).

The damn indicator is still lit.

Any suggestions?

Thanks in advance!

[frw73]

22 reads and no replies.
AND there's a new thread on 'check engine light on after gas' in this forum.
Oh well.

Problem seems to have sorted itself out after I re-filled with a new tank of 94 octane gas, and the computer is not retarding the timing.

[97alpineM3]

To be honest with you.. if probably just a warning for you to only use a higher octane.. I'm not sure what the newer e46 M3s call for... in octane.. but I think.. I've heard another person on these forums say that their check eng. light has came on due to improper fuel octane... hopefully that will fix your problem.

Good Luck...

Les

[gpoints]

I run 91 all the time w/o problems. Wierd???

[frw73]

OK scratch that.
Stupid light is on AGAIN this afternoon!
Looks like I'm off to the stealer tomorrow if they can 'fit me in'.