So I put on the C&L racer CAI about 4 years ago. Reltively problem free, and about a month ago I noticed the car wanted to die whenever I put in the car in neutral. Under load the car drove perfectly, but after driving, when I would stop, the rpms would dip below 500 (where the engine sometimes dies) or it would shoot up to 1200ish then teeter totter back and forth until the reached the normal 800 where it remain fine.

So I decided to get a brenspeed tune (I was using a canned diablo tune, so I attributed the problem to that.) Install the brenspeed tune, sure enough, problem remained. Only this time, I drove it enough to get a check engine light. Hooked it up and gave me codes p2106 and p2135 which correspond to TSB 05-14-4. Only problem is I didn't want to take it ford with a CAI and tune installed, so I put the stock intake and tune back on and problem gone. WTF!!! Anybody with this problem and they put stock back on and the problem went away? I don't feel like spending $600.

Thanks for any help!

 

If Ford performs the TSB, they'll reflash your PCM (per the TSB) and then your tune won't reinstall. Have you tried clearing the codes by disconnecting the battery for 20-30 minutes? While the battery is disconnected, clean the TB.

When was the last time you ran a can of SeaFoam or some other quality system cleaner thru a tank of gas?

 

I haven't ran any seafoam, but really don't think it'd do much. If the car runs fine with the stock tune and air filter, but erratic with the cai and tune, I'm thinking it has something to do with the CAI or the MAF (not the tune because the problem remains for two seperate tunes).

But actually, its starting to happen. I've been driving the car all day and its starting to show signs of what it did with the CAI and tune on. I *hope* I get a CEL light because the dealer won't do much without one. Thanks for your help nuke

 

Custom tunes are more sensitive to TB, MAF, injector, and probably other issues compared to the stock tune so I still recommend cleaning the TB and MAF (pretty simple and there's a recent How-To post for the TB cleaning from Brenspeed. The MAF can simply be slipped out of the intake tube and sprayed with the CRC MAF cleaner or other products) and running a good system cleaner to hopefully take the injectors out of the equation.