CEL came on today...

[KPC1.8TQuat]

03 1.8T, 74,000 miles stock. Driving in to the office today at a red light my CEL comes on. Not blinking. Car has been running fine. Only thing I even remotely noticed was that sometimes while at idle it seems to drop in revs or hesitate for maybe half of a second. Other than that the car is mechanical flawless.

Bringing it to autobahn performance in Peabody Mass at 1pm today. Not my usual shop, but they are less than a mile away from where I work.

Any thoughts?

[Papachristou]

throw a dart at a bentley and you have have the same chance of guessing whats wrong... just get the code scanned

[KPC1.8TQuat]

throw a dart at a bentley and you have have the same chance of guessing whats wrong... just get the code scanned

Yeah, but what I meant was to find out if anyone else is experiencing the same hesitation at idle for half a second.

[dougyfresh]

03 1.8T, 74,000 miles stock. Driving in to the office today at a red light my CEL comes on. Not blinking. Car has been running fine. Only thing I even remotely noticed was that sometimes while at idle it seems to drop in revs or hesitate for maybe half of a second. Other than that the car is mechanical flawless.

Bringing it to autobahn performance in Peabody Mass at 1pm today. Not my usual shop, but they are less than a mile away from where I work.

Any thoughts?

Could be a mis-fire. That'll throw a CEL.

Is your valve cover gasket leaking around the spark plugs?

How old are your coil packs?

When was the last time you replaced spark plugs? What plugs?

Original, factory, software? misfires are rare then, unless something is causing them like the questions I posed above.

[KPC1.8TQuat]

Could be a mis-fire. That'll throw a CEL.

It's not a blinking CEL which is usually conclusive for timing or misfires

Is your valve cover gasket leaking around the spark plugs?

No leaking oils anywhere.

How old are your coil packs?

I just had my shop put in 4 new R revision CP's last April

When was the last time you replaced spark plugs? What plugs?

Plugs are Bosch +4's with less than 10k miles, not copper but I'm stock so no need.

Original, factory, software? misfires are rare then, unless something is causing them like the questions I posed above.

I really don't think it's a misfire. The car has normal power when it's not at idle. Like I said in my first post, the car is running absolutely fine. If not for the CEL, I wouldn't notice anything really wrong with her. My vacuum at idle is normally around 20mmHg but I'm noticing it's down to around 16-17mmHg once the car is warmed up. Could be a leak somewhere?

[absolutegtr]

I would say........emissions related

[dougyfresh]

It's not a blinking CEL which is usually conclusive for timing or misfires

Not exactly true. I get (random and intermittent) mis-fires at cold start-up and its a solid CEL. [That's just because my tune is no where near what it needs to be right now.]

[Molotov]

bad o2 sensor!

I just wanted to throw a random guess out... just wait for the scan

[KPC1.8TQuat]

Just got my scan done.

I don't remember exactly what he said, but something about one of the banks running lean. Most probably cause is a bad MAF, or a vacuum leak somewhere. Code was cleared and the car is safe to drive, only drawback until it's fixed is a slight dip in my fuel economy.

Looks like a MAF party this weekend! WOOT!

Thanks all.

[aaaudiprotein]

^^^ Before buying new MAF, try to clean it. They sell those MAF cleaners at Autozone and etc. Also, there is a chance that one of the vacuum hoses broke. Check them!!!

[coowhip]

I tried to clean my MAF and it didn't help, so I had to buy a new one. Worked great. ECS tuning!! Same symptoms except my car would actually die at a red light.

[KPC1.8TQuat]

I tried to clean my MAF and it didn't help, so I had to buy a new one. Worked great. ECS tuning!! Same symptoms except my car would actually die at a red light.

Yeah, I'm going to take a look at the MAF tonight when I get home and see what shape its in. I'll most likely just buy a new one.

Thanks everyone.

[MikTip]

throw a dart at a bentley and you have have the same chance of guessing whats wrong... just get the code scanned

People dont want to hear the truth!

They want everyone to play their "CEL Guessing Game!"

A prize should be offered for the most correct/nearest guess...

[mattman]

^^^ Before buying new MAF, try to clean it. They sell those MAF cleaners at Autozone and etc. Also, there is a chance that one of the vacuum hoses broke. Check them!!!

you can also use electrical contact cleaner to clean your MAF

[aaaudiprotein]

Yeah, I'm going to take a look at the MAF tonight when I get home and see what shape its in. I'll most likely just buy a new one.

Thanks everyone.

You wouldnt really see any difference if its dirty or not.
Are u chipped by any chance? Open your hood while car is on and listen for any air sound. Also, when the engine is cold, try to look over all those vacuum/boost hoses.