spectre30068

Hello fellow stang-ers. I have an 05 GT, with a JLT intake and Predator tuner. I've changed the octane/tuning several times in the past with no issues. However, I recently bumped back up to the 93 octane tune, and as soon as I did, I got the check engine light. After driving it around for a while, the light never went off, so I went by an auto parts store and had a scan done. What they gave me was the following: U1900 - controller area network communication malfuntion. P0171 - Bank 1 system too lean. P0174 - Bank 2 too lean. P0300 - random multiple misfire. P0316 - misfire detected on startup. and, P1000 - OBDII drive cycle test not complete.
The car seems to be running fine, but I have to get the emissions tested within the next couple of weeks and of course it won't pass with this stuff going on.
There may be some way to clear the codes with the tuner, but I haven't messed with it yet. Suggestions? The car's only got 54,000 miles on it, so I wouldn't think I need new plugs, etc. Thanks for any help...

Glenn

I think I would start with returning it to stock and then re install the tune. Install the one that didn't throw any codes.

05YellowGT

Do what Glenn said and also contact who ever you got the tunes from. The P1000 is just because you re-flashed the tune recently and will eventually go away, and it will tell the inspection station if it's still there. Also when you re-flash it clears the adaptive memory, so if you had some sensor going bad the computer would have used the save values until then. I've had that happen over the years ...

dmhines

In GA if you have a P1000 .. they will not let it pass inspection ... so make sure you drive the car enough to get rid of it.

spectre30068

Thanks for the replies, fellas! I haven't had a chance to mess with the car until a few minutes ago, so here's what I did: I'd forgotten that the tuner has a 'clear codes' function (never had to use it before), so I plugged it in and did that. Bingo - the check engine light went away. So I fired up Sally to take her for a ride around the neighborhood. When I started the ignition, though, the engine sort of bogged down like it was going to stall, but it didn't. Car drove fine around the neighborhood, and didn't act like it was going to stall any more, until I pulled back into the driveway and it bogged down a little bit again, but didn't stall. So, I've still got the same 93 octane tune on there, with no more check engine light.
I am aware that I'll have to put some miles on it before the emission test...I once had changed the tune a day or two before emissions, a few years ago, and didn't pass. The tech informed me, though, that since I had just retuned, putting a couple of hundred miles on it would probably take care of it, and it did. I didn't realize that was reflected by the P1000 code, however...(thanks 05YellowGT!)
So do you guys think my problem is solved, without having reflashed the tune, or not? Plus, there was the strange engine bogging issue, which hopefully will not be present the next time I fire her up. As you can tell, I'm no automotive whiz.
Dmhines - I am in GA, by the way. East Cobb here.

Thanks for your help and suggestions, guys.

spectre30068

Ok, so here's what has happened so far. I first switched back to the mid-grade octane tune, which was the last tune I had on there with no problems...had been running that tune for quite some time. Got the check engine light again.

I contacted AM/Bama and ordered new tunes, have not received them yet.

In the meantime, I went back to the stock tune. No check engine light on the first drive, but today, the check engine light came back on again. I haven't checked, but I'm sure the codes are still the same.

I'm about to pull my hair out over this. Awaiting response from AM on what they think my next move should be. Am wondering if I'm going to have to break down and take the **** thing to a dealership and have them do whatever they have to do to fix it. Really, really don't want to spend the $$ though, and time is a huge issue for me.

dmhines

What's the code? If it's back to stock and still getting codes then it's not the tune.

spectre30068

P0171, P0174, and of course P1000.

dmhines

If you get those codes with stock tune and stock airbox you have a leak somewhere. Either intake is sucking air or vacuum leak.