flag_route

So I'm not knowledgeable with cars but decided to go with a more hands on approach for my 06 A8L when I got it a 6+ months ago. My drivers side headlight bulb went out so I ordered 2 to replace both sides. I started with the passenger side and after much much struggling(accidentally pulled out the turn indicators which were a bitch to get back in with that tiny space) I got it done. I followed instructions from

https://www.audiworld.com/forums/a8-...embly-2616646/

And

https://www.audiworld.com/forums/a8-...nsive-2788968/

I decided to replace the air filter while I was at it since the 2nd link recommended it.

I started the car after I finished the passenger side to check if everything worked but I got a check engine light and the ESP light. I'm not sure what I've done to get those 2 lights on. I only removed the air filter cover, air filter itself, passenger side wheel, wheel liner, small metal box covering the xenon headlight bulb. Those lights never even flashed once before.

I'm still a bit clunky with the search bar(it seems to show all the search results for every model but when I add in 06 A8L nothing I need shows) so any help towards a certain direction would be much appreciated. Thanks in advance.

Oh I forgot to mention, I'll be going to an autozone tonight since a lot of threads seem show that getting the codes from the free check engine light check is necessary.

haggisuk

Most likely you have forgot to plug the MAF sensor wiring back in or if you didn't remove it you may have strained the wires and broken them.

Have a look at the plug that connects to the sensor at the air filter.

MP4.2+6.0

+1. As you slide toward DIY, buy the VCDS cable for scanning. The AutoZone code reader may work in this case, but the Ross-Tech tool is much better and would allow you to diagnose this and 50 or 100 other repetitive areas, let alone esoteric stuff.

flag_route

I didn't unplug it and I think I may have strained the wires. I hope they aren't too difficult to replace(so I can do it myself). Is it okay to drive the car while the sensor isn't working?

Also any idea on why the ESP light came on? I did turn on the car while the passenger side was jacked up without a wheel on it. I tried turning the car on again this morning and it's still there.

flag_route

Oh man just checked out the Ross-Tech and whoo they looked pricey. Thanks for the tip, looks like I need to save up a little.

MP4.2+6.0

One time investment and single most valuable tool on a modern Audi. Can always be resold too; same (CAN) cable works on all of them and software is lifetime.

Mike141

The Ross Tech cable is a necessity with these cars. Try to find a used one on ebay if brand new is too expensive for you. If you plan to do your own oil changes, make some mods on the settings, not only used for the occasional (hopefully rare) CEL, you're gonna wish you had it.

dvs_dave

You can also use vcds as a generic OBD 2 code reader for any vehicle so it's not totally limited to VAG products.

I've used it on my Cooper S a few times to diagnose a faulty high pressure fuel pump.

haggisuk

Yeah the wires should be easy enough repaired, your esp light is probably on for the same reason, maf is used in calculations for gearbox as well as fuelling.

when the maf is disconnected the engine and box revert to a default make do map until you get it fixed, but that by no means is reason to leave it for ever and bang 100's or 1000's of miles on her.

P.s I trust you put the suspension in jacking mode while you had her jacked up?

If your going to do the wiring repair you will need one housing and five contacts, i you order 5 you will get 5 pieces of wire with a contact either end so effectively 10 contacts.

MP4.2+6.0

Get plugs connected correctly again and clear the codes before doing any wiring surgery in case it was just transitory/from unplugging. Both CELs and I think ESP are not things that necessarily self clear. If codes/lights come back, then pursue.