[dannykao]

Hello,

I have been searching for this problem on the forum and only saw MT fixes as well as air intake tube or AC belt rubbing harness. If anyone has a fix for the problem I am experiencing it's greatly appreciated. Background:

I purchased an entire flex fuel kit from one of the forum vendor, including Kooks 1 7/8 long tube header, HP Tuner, ECM flash, and flex fuel sensor, harness and fuel line. After the header install without adding the Flex Fuel sensor, I asked if I could installed the tune and was told OK by the tuner. That was the last time I heard from the tuner even after repeat attempts of contacting him.

I went out for a drive, and within 10 minutes every check engine codes existed came out. The car went into limp mode and I limped it home; and one of the error is fuel sensor error. I then flashed it back to stock because tuner won't respond to my calls/texts; the car ran rough but kind of normal after, but secondary O2 sensors error persists.

I then installed the fuel sensor kit, flash to the custom tune. All CELs were cleared, and went out for a drive. The car seems to run a little rough but ok. However as soon as I try to full throttle, the rpm hits 5000 then I get a hard fuel cutoff. The car will die on it's nose, pause 2 seconds like it's going to stall, then slowly comes back to normal.

I decided to swap back to stock tune and leave the header on and remove all flex fuel sensors/harness. The car ran better then the tune in normal street driving. However, whenever I am going full throttle, it will cut off the fuel again around 5000 rpm and almost stall.

I have tried to run without traction control or stability control. Tried in Tour/Sport/Track mode. And manual shift. In manual shift mode, it will do that around 4000 rpm in 1st gear, and 4500-5000 in seconds gear. Basically if I go hard on the throttle, it will have a very abrupt fuel cut after about a second or so; this takes any weekend autocross out of the question.

I am wondering if anyone has similar experience as this. I don't know where the tuner went, but since I was the dumb one to trust his product, it's my bad. Now I am back in 100% stock tune and the problem is still there, and I need help otherwise my autocross season is practically over before SCCA Nationals unless I can figure this out.

Any help is greatly appreciated. Thanks!

[jdasnt3]

I can only give you advice based on my personal experience. I am sure there are other options. Please give Jeremy Formatto a call from Fasterproms. He does get up to your area and he'll be able to help with the tune and flex fuel sensor. I know it isn't the answer you need, and you'll get some other tuners on here to pledge their help.