Hey everyone who stumbles along this thread, here's the story.
Background: I own an 03 cobra with a catless x pipe, no other mods.
I got a random p0174 code, bank 2 (driver's side) lean, about a week ago.
I immediately got a smoke test, no leaks according to the tech.
Cleaned the MAF and the throttle body.
Still threw the code.
I checked my long term fuel trim with my SCT and got random spikes of 25 percent for bank 2.
Bank one looked normal and consistent.
I noticed that it sounded like there was almost zero back pressure in the exhaust and that the car was considerably louder, so I thought I might have an exhaust leak.
My mechanic was convinced it was a faulty O2 sensor, but I disagreed completely.
Against my better judgement, I let them install a new 02.
Afterwards, I was still getting the p0174 and running a high long term fuel trim.
Well, today I jacked the car up and took a quick look at the exhaust.
And what do you know, one of the nuts had come off the flange for bank 2's down pipe.
How the tech I took it to didn't notice this while changing the 02's, I have no clue.
So I tightened a new one down and the existing nut (which had come loose).
I noticed that there seemed to still be a tiny gap from the pipe being poorly constructed, but the exhaust had quieted down a lot.
I reset her and did some data logging.
Now she's fine cruising and most of the time at idle, but after a few short runs, her long term fuel trim started to slowly rise while I let her idle. When I shut her off, she was at 1.195 long term fuel trim.
I'm lost at this point.
My next move is going to be putting the stock exhaust back on.
Any other ideas?
Any comments would be appreciated...
Background: I own an 03 cobra with a catless x pipe, no other mods.
I got a random p0174 code, bank 2 (driver's side) lean, about a week ago.
I immediately got a smoke test, no leaks according to the tech.
Cleaned the MAF and the throttle body.
Still threw the code.
I checked my long term fuel trim with my SCT and got random spikes of 25 percent for bank 2.
Bank one looked normal and consistent.
I noticed that it sounded like there was almost zero back pressure in the exhaust and that the car was considerably louder, so I thought I might have an exhaust leak.
My mechanic was convinced it was a faulty O2 sensor, but I disagreed completely.
Against my better judgement, I let them install a new 02.
Afterwards, I was still getting the p0174 and running a high long term fuel trim.
Well, today I jacked the car up and took a quick look at the exhaust.
And what do you know, one of the nuts had come off the flange for bank 2's down pipe.
How the tech I took it to didn't notice this while changing the 02's, I have no clue.
So I tightened a new one down and the existing nut (which had come loose).
I noticed that there seemed to still be a tiny gap from the pipe being poorly constructed, but the exhaust had quieted down a lot.
I reset her and did some data logging.
Now she's fine cruising and most of the time at idle, but after a few short runs, her long term fuel trim started to slowly rise while I let her idle. When I shut her off, she was at 1.195 long term fuel trim.
I'm lost at this point.
My next move is going to be putting the stock exhaust back on.
Any other ideas?
Any comments would be appreciated...