I also have a question on code 17843 secondary air inject...

Hello, my name is \*\*\*\*\* \*\*\*\*\* I will be helping you with your question today. I've been working on Audis for over 30 years now, so I should be able to help you through this. Please understand that some of my suggestions may require special diagnostic tools and equipment that many home mechanics may not have, but are often required. So, my first question is whether you're planning on performing your own repairs, or are you wanting to be armed with information before bringing it into your mechanic? **Also, the site automatically prompts for a phone call. It's very rare that I'm available by phone, so let's hold off on that for now. If needed after we exchange some information, I will do my best to take the time for the call.** This one sounds pretty familiar. Did you replace that exact relay that we discussed on Friday. Can you please take a picture of it in place in that relay panel and point to it?

I actually haven’t but I haven’t been able to find the 373 relay online but I’m pretty sure it might me the one u showed you online but it just doesn’t show the number on itBut so your saying the location is on the engine of the passenger side I haven’t checked but I’m not sure if there’s something for relays there on that side but once the car is back I will check

Take a picture of the relay panel on the right side of your engine compartment and post it here. I will edit the picture, circle the relay and post it back

Are you able to just circle like which side of it it should be on

You can click picture for full screen

Ok, I would have thought that you already had the relay panel exposed. It's in here.

It's either in position 3 or 4, has 373 printed on it as I mentioned. If you haven't opened that box up, then that is the reason you haven't seen the 373 relay. Attaching parts info again showing exact location.

Ohh okay well when I’m with the car again I will check it out and open that box up

Yep, mentioned that on Friday also, that it's in that location.

I just haven’t been able to find the exact relay online I mean u have found the one I showed you with the exact part number but it doesn’t show the 373 printed on it or maybe it is but just doesn’t show that angle but maybe it should work if it’s same part number right

Just use that part number, buy it from a dealer so you know it's genuine. Don't worry about the 373 printed on it. A new relay might not have that. The 10-character part number (4H0 951 253 A) is the important part. It could even have 643 printed on it. But again, this printed number on the replacement relay doesn't matter.

if it has the exact same part number you told me is it ok if it has a number like 600 and something

Yes. Ignore the printed 3-digit number on the new relay.