Recently switched out old spark plugs on 2002 a6 3.0 for NGK platinum plugs. I was having rough idle afterwards when the MAF was plugged in, so I disconnected it. That solved the problem. for a little bit but the idle is once again rough, any ideas?

Btw. I left the spark plugs pre-gapped and I feel like my car has lost some power.

 

Pull the codes (free at Autozone or =) and post. You may have a bad coil(s). I always check the spark plug gap, even if it comes correct from the mfr. Make sure your air filter is clean.

 

Air filter is clean, replaced about 5000 miles ago, replaced Ignition Coils about 1000 miles ago(recall service.) So it shouldn't be either of those. Would I have to buy a certain tool to check the gap?

 

Spark plug gapping tools are cheap and available at all auto stores and Walmarts, etc. I have always used either the wire gauges or the metal strip feeler gauges (can also be used to adjust valve lash in the good old days). Avoid the circular metal ones that are given away for free.

 

If your car ran fine before the plugs and is now running rough after the plugs, then I would say it is plug related. Start by making sure that your coils are set properly. Then remove the plugs and check the gap. FYI, multiprong plugs are factory gapped. Some plugs may have been subjected to rough handling and messed up the gap. You should be almost be able to tell by just looking and comparing the plugs. BTW, did you get the correct plugs?

 

There are 9 years on tthe wires -- Makes me think he messed them up when he changed the plugs.

Step #1 make sure the wires are pushed all the way on. (if you have individual coils make sure the contacts are right)

 

It's definitely the MAF. Regapped the spark plugs, were all at like .035, supposed to be .044. Ran perfectly fine until I plugged the MAF back in and started going bucking Bronco on me again.

 

Might be a vacuum issue. Had the same problem before with the exact same situation before I realized I had knocked a hose loose. Unplugged MAF was good and plugged in MAF ran like crap. Found the loose hose, connected the hose and the MAF, and it ran fine.

 

Turns out it wasn't Spark Plug related at all, merely coincidental. The Breather Hose had broken, so I mended it for the time being, and am getting the 150$ hose in later this week.

 

ecstuning has the hose for 50 bucks