P050A Cold Start Air Idle Control: Repeat code 3 times!!!

[@udible]

So two months ago I get a check engine light, had the codes ran at my preferred performance shop. Got the EVAP and P050A codes. Car is under warranty so I take it to Audi. They change the EVAP, cleared the codes, figured the P050A was simply related and did nothing further. 2 weeks afterwards check engine light comes on again. Same repeat code. Take it in and they replace the throttle body. 2 weeks later, this passed Tuesday it comes back again. Dealer had it for 2 whole days, they give me a call asking if I was sure I never had the car tuned and didn't just turn it off before bringing it in? Well first off I know that's bs because they have scanned and even updated my software on the first check, but anyway I played along. No I haven't had the car FLASHED, it's still under CPO warranty and I really don't want to lose that amount of protection. Well, the service guy tells me they brought in an Audi specialist to look into it being that it's the third time I've come in for this. And the only thing they can come up with is to remove my Rotomass UDP and install the stock pulley and return my turbo inlet hose to stock; I have the silicone inlet hose. Once I've done that, bring it back in to have the codes cleared. Drive it around and go from there. So for one, I hardly doubt a pulley has anything to do with this code and for $105 to remove it, let Audi d*ck around with it to find out it has nothing to do with it, then pay another $105 to reinstall without reimbursement is ridiculous. And if I do happen to do that I'm selling the damn thing because it's a $225 part and not worth it. But anyway, I'm wondering if anyone here has ever experienced the same problem. Only modes are APR catback, afe drop in filter, Rotomass UDP, and silicone turbo inlet hose. Also, the rep says they don't see this problem at all, only once or twice and it's been combined with a FLASHed car. Tomorrow when I stop by to pick up my car I'm going to have a longer discussion with the guy explaining the none likelihood of the pulley having anything to do with it. I'll replace the inlet hose and filter but I think they're being incompetent about trouble shooting. Thinking maybe a leak or somewhere for that matter, what do you guys think?

[bdons]

I am reading the same fault code with the same intermittent time line. I have the same mods on my 13 A5. Eurocode pulley, turbo inlet, intercooler and piping, flashed, etc. I'm going tomorrow morning to have them look at it and I'll let you know what they say.

[amz]

Gotta pay to play man. That being said, have you tried cleaning your MAF?

[@udible]

Thanks man. I'm going to pick her up today and talk to the manager. I'll let you know how it goes.

[@udible]

Gotta pay to play man. That being said, have you tried cleaning your MAF?

I understand the pay to play but that's not my real argument. My complaint is I don't feel is related, I could be wrong though but doubt it. And it's really not a hp maker anyways so why spend an extra $200 removing and replacing it is where I'm coming from.

[van462]

The P050A code from what I'm reading is generated if the ECU doesn't detect the proper amount of air used (MAF) by the motor in the first 10 seconds after a cold engine start. It takes usually 2 occurances to generate a fault. The ECU uses the throttle body to adjust air flow to meet desired amount. As it is a cold start the ECU can't use the O2 sensors to validate what is happening yet. As amz mentions a MAF cleaning would be a good start. Any vacuum or boost leaks should be detected and generate additional codes once the engine is warm. So those are less likely. The only other sensor that should be involved is a crank position sensor to validate the RPM and coolant temp sensor to validate its a cold start.

[@udible]

The P050A code from what I'm reading is generated if the ECU doesn't detect the proper amount of air used (MAF) by the motor in the first 10 seconds after a cold engine start. It takes usually 2 occurances to generate a fault. The ECU uses the throttle body to adjust air flow to meet desired amount. As it is a cold start the ECU can't use the O2 sensors to validate what is happening yet. As amz mentions a MAF cleaning would be a good start. Any vacuum or boost leaks should be detected and generate additional codes once the engine is warm. So those are less likely. The only other sensor that should be involved is a crank position sensor to validate the RPM and coolant temp sensor to validate its a cold start.

van462,

Thanks for that insight. I was told yesterday the car would be ready for pick up today right. So I called and it turns out they were still working on it and I was then informed to await another phone call to pick it up. Well I never received a call from Audi today but I'm not worried about it because maybe they're taking the extra time to dive into it. Anyway, should I arrive for pick up and they're still wanting me to remove and replace parts I'm going to bring up your points you've brought up. I just wonder how receptive they'll be to my suggestions, hmmmmmm.

[van462]

Also with your previous EVAP fail the N80 valve is suspect. On a cold (also using the coolant temp sensor) start it should be off and not allowing evap gases to the intake. Once warm it should duty cycle and meter in gases. You can often hear it clicking. I would think they would do a vacuum test on it with it unplugged to see if it fully sealing and not causing an air leak. That might not cause an intake leak fail when warm as a leak there is sort of factored in.