flag_route

I was driving home from work and when I was stopped in traffic the check engine light came on and the car started shaking real bad.

I'll be taking it in to the mechanic to see what's wrong with it but does anybody have any ideas on what could be wrong?

I'm guessing it could be a spark plug, coil pack or ignition control module from googling the problem.

what usually goes out first on a 2006 4.2 A8L with 130k miles?

Also how bad is it to drive the car 20 miles at highway speeds while the light is on? I need to drive it to work tomorrow and go to the mechanic on sat. If it's really bad to drive it I'll just uber there.

Jack88

Look, sounds like a misfire, but that's not definite. Even if we knew that for sure, there are a million reasons why it would do that. Now, in some cases, it would be fine to drive it. In others, you might destroy your motor or make the problem more expensive for yourself. In short, best not to drive it at all if you have a choice. When you go to the mechanic, take it easy on the old girl. You really need a proper VCDS scan, but even a regular one could at least point you in the right direction.

ltooz_a6_a8_q7

Some vacuum hoses at the MAF or Throttle body popped. Start looking under the hood, check all the vacuum hoses. The car don't just die... Something very simple and these tiny hoses can really cause the symptoms you have. If you take to the shop, they will find something, but they can't just charge you for broken/popped out of connectors hoses. I've fixed so many misfiring by just finding these hoses.

Cheers,
Louis

MP4.2+6.0

Add bad fuel pump to the list of possibles. You really need a VCDS scan to avoid guessing, though as stated for motor only a simple OBDII code scanner would likely provide at least some diagnostic info.

TSHong

You probably wont blow your motor up but lets say if it's a misfire and you could potentially damage your catalytic converters. I would not risk it.

flag_route

where can I find the MAF and throttle body?

flag_route

yeah I really need to. I usually just bring it to the mechanic to find out what's wrong with it and fix it myself.

the vcds scanner I found was a bit too pricey for me.

ltooz_a6_a8_q7

Air cleaner is on the left with MAF with the pipe to the throttle body under the 4-ring cover in the back. Lift the 4 audi ring cover up, all the hoses are under there. Visually inspect them or just tow the car to the shop and wait for the bill. Most of people are pessimistic and think of the worst. I don't, therefore I've never replaced a good part.
http://www.dognmonkey.com/audi/98-a8...-problems.html
Cheers,
Louis

Jack88

Absolutely true. Now, I should note there is a hose that hooks up from below that is covered by the MAF and the big tube on mine that had been broken. Easy to break even changing air filter. Worth a check, easy enough, even with it assembled.

2001 S8

Below is an option to the pricier Ross-Tech. It's probably not as robust but better than a generic reader.

• https://www.ecstuning.com/b-obdeleve...024871obd01~a/

Good luck.