2.0Tfsi, running too lean fault code.

[stoney369]

Engine management light came on, had it scanned at a local Audi specialist Saturday, came back as running too lean. The guy suggested it was one of two things, either a change of fuel (shell v-power to a regular unleaded) or a throttle body fault. The garage turned the light off and we put it down to me changing my fuel from v-power to regular unleaded, drove away and after about an hours driving light comes back on. Cars going back in this afternoon so they can look at it again but has anyone got any suggestions or come across this themselves?

[aluthman]

I fail to see how it could be due to the brand of fuel. I guess throttle body is a possibility, but I highly doubt it without other codes. I would lean towards an O2 sensor. How many miles are on the car?

[stoney369]

About to hit 85k, I thought it would be a bit too good to be true being the change in fuel, had the car 2 years now and on the off chance I can't get to a shell garage to fill up with v-power and used a regular unleaded it's never been an issue before.

[teckk]

Regular gas is definitely no bueno for our cars even if you can only find 91 octane thats still a little safer to run than regular gas but i think aluthuman might be right when you go back see if you can find out what codes their vagcom pull up an post them up

[stoney369]

Just back from the garage, unfortunately I haven't got the fault codes other than it's running lean at idle. The garage have changed their mind on it being a throttle body problem and are now suggesting it's either my cam follower or my fuel pump? They've ordered in a new cam follower and it's getting changed Saturday morning, I'm a bit worried about going down this whole guessing game route changing things until we fix the fault.... Apparently it's making a loud ticking noise and is "sounding like a diesel" in his words but these engines are renown for sounding a bit like that at idle with the bonnet up aren't they? It's not sounding any different to me and I've had it 2 years now so I'd like to think I know the car quite well by now. Any more suggestions?

[V2Rider]

Just back from the garage, unfortunately I haven't got the fault codes other than it's running lean at idle. The garage have changed their mind on it being a throttle body problem and are now suggesting it's either my cam follower or my fuel pump? They've ordered in a new cam follower and it's getting changed Saturday morning, I'm a bit worried about going down this whole guessing game route changing things until we fix the fault.... Apparently it's making a loud ticking noise and is "sounding like a diesel" in his words but these engines are renown for sounding a bit like that at idle with the bonnet up aren't they? It's not sounding any different to me and I've had it 2 years now so I'd like to think I know the car quite well by now. Any more suggestions?

Cam Follower/Cam/HPFP is exactly where I wuld look, especially with the CEL. Have you ever replaced it? (cam follower). Should check it every 15k or so, they are notorious for going out. 15 minute job, very very easy DIY

[LoKisSpYdR]

OK, look our cars sound like a diesel, that's because like a diesel they're direct injected.
OP, using a lower grade of petrol may give you a lean code, but I'd doubt it. That said, it's very easy to check. fill her up with a known good fuel, like V-Power.
As V2 said, if you haven't checked the follower, do that as well.

I personally would lean toward an O2 sensor, as Adam stated to above, or an unmetered amount of oxygen getting into the system, which would likely trigger other codes as well.

[aluthman]

While changing your cam follower is always a good idea, it's not making you run lean. It sounds like the shop is just guessing at your expense and doesn't know what it's doing. I would consider taking it to the dealer and just having them diagnose the problem.