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Check Engine Light After Tune...

11236 Views 7 Replies 5 Participants Last post by  JJhummus
Hey Everyone,

I need some help....

I installed the Trifecta tune for my 2011 Regal T07 Manual Transmission about a week ago. About 2 days after the tune, while my wife was driving the car, the check engine light came on. I ran the codes when she got home and it said P2261, which is the Turbo Bypass Valve. I cleared the code and hoped that it was just a fluke and wouldn't come on again.

However, a few days later, which was today, the check engine light came back on, this time while I was driving. It's the same P2261 code and now also a P0171 code (Fuel Trim System Lean, Bank 1).

Have any of you heard of this before? I assume it has something to do with the tune. What do you recommend I do?

Also.... I did start using E85 gasoline at the time of the tune. The car has about 15k miles.

Thanks!
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Did you contact the company you got the tune from?
I just contacted WOT-Tuning/Trifecta about the issue. They said....

"P2261 indicates a mechanical problem with the bypass valve. Usually meaning it is getting stuck open. P0171 is likely being triggered because of it.

You'll need to inspect the bypass valve and either repair (sometimes it will just need to be re-lubricated) or replace it.

This is not something specific to the tune though (it happens to stock vehicles too), so you'll likely be able to get it fixed under warranty if you flash back to stock and take it in. The chances of it happening again with a new bypass are slim"


It's at the shop right now getting the Bypass Valve re-lubricated. If it comes on again I'll have them replace it with an upgraded one from Forge Motorsport. I'll keep everyone posted.

WOT-Tuning/Trifecta has been GREAT, by the way. I would strongly recommend their tune.
what are you using to load/reflash the tunes? Do they sell you a controller of some sort?
Yes, they sell you a special cable that allows your laptop to be connected to the vehicle.
skillz, how do you like the tune? would you reccomend it? what did it cost you
I am waiting for HP Tuners to get theirs on the market. I have it already for my GTO. GM must have these things running pig rich cause my exhaust tips are always black with soot. Dealer said its normal.
I am waiting for HP Tuners to get theirs on the market. I have it already for my GTO. GM must have these things running pig rich cause my exhaust tips are always black with soot. Dealer said its normal.
Me too, just waiting on HPT. It is definitely rich as mine looks like a diesel when you put your foot down and gets worse gas mileage than my G8 thats making 400+rwhp.
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