Engine Fault code help please!!

[Mad Hatter]

Hi, I recently logged mi Boss in hopes of getting a tune from AED. I have been having P0420 powertrain codes saying Catalyst system efficiency below threshold and P2254 Powertrain: O2 sensor negative current control circuit/Open bank2 sensor 1. I had thought they had to do with the Kooks LTH and Cats and could be fixed with a tune.

After reviewing my logs, Shaun made it very clear I have to fix the engine issues ASAP and he would not tune the car. During the logging another error code came up, P0451 Evaporative emission control system pressure sensor range/performance. Fuel tank pressure lower the specified value.

Any incites on where to start? Was thinking I need new O2 sensores, but the tank pressure code is new to me. Taking the car into a shop tomorrow (New shop, old shop just cleared codes).

 

[TMSBOSS]

Hi, I recently logged mi Boss in hopes of getting a tune from AED. I have been having P0420 powertrain codes saying Catalyst system efficiency below threshold and P2254 Powertrain: O2 sensor negative current control circuit/Open bank2 sensor 1. I had thought they had to do with the Kooks LTH and Cats and could be fixed with a tune.

After reviewing my logs, Shaun made it very clear I have to fix the engine issues ASAP and he would not tune the car. During the logging another error code came up, P0451 Evaporative emission control system pressure sensor range/performance. Fuel tank pressure lower the specified value.

Any incites on where to start? Was thinking I need new O2 sensores, but the tank pressure code is new to me. Taking the car into a shop tomorrow (New shop, old shop just cleared codes).

This may sound a little off course, but.... Check the battery and charging system first. The reason I say this is because it appears you have several unrelated codes all at the same time. The common denominator may be the electrical system.

Check voltage on the battery engine stopped and with the engine running, battery charging. Then go from there.
12 ish for the battery engine off. High 13's to low 14's with the engine running is a good rule of thumb.

Good luck.

 

[Mad Hatter]

This may sound a little off course, but.... Check the battery and charging system first. The reason I say this is because it appears you have several unrelated codes all at the same time. The common denominator may be the electrical system.

Check voltage on the battery engine stopped and with the engine running, battery charging. Then go from there.
12 ish for the battery engine off. High 13's to low 14's with the engine running is a good rule of thumb.

Good luck.

Thanks!, looks like I might need it! 14.6V engine stopped and 16.7 engine running. Does not sound very promising. Also noticed a few days ago, that I had problems filling up at a gas station. The pump trigger would go off every couple of seconds. Looks Like I have some kind of pressure relief problem as well. Come to think of it all my engine codes started after I had my alternator replaced after it quite charging. I put in a new one and changed battery.

 

[TMSBOSS]

16.7 does sound high.

Good luck tracking down the cause.

Does sound like the new alternator.

Did you replace with the Boss specific unit?

 

[Mad Hatter]

Yes I did....at least thats what I bought online..... now I had better check LRS sent the right one!

 

[Rick_ND]

Had the fueling issue on my Nissan Sentra. In the end it was the evap canister vent tube plugged with mud. I cleared it out and was ok after that!


Sent from my iPad

 

[Mad Hatter]

Just got a call form the garage, wanted me to stop by and see the electric Steering go crazy by itself........ ??

 

[TMSBOSS]

Did they mention voltages at battery and alternator?

 

[Flyboygsxr]

I'd make sure you got the right alternator and battery. Was it a Ford OEM alternator?

 

[Mad Hatter]

The battery was a no name brand with the right amps etc, the altenator is #M8600M50BALT. Supposed to be the Boss unit complete with belt etc.

 

[Flyboygsxr]

I would double check that and make sure you got it from a reputable source. A lot of aftermarket alternators are just refurbished units.

 

[VoodooBoss]

I was told very early on from a Ford engineer to be careful with replacement batteries. This was specific to the 12's as the 13's weren't being made yet. My memory is a bit foggy on this but he said something along the lines of the cars being sensitive to the proper voltage.

@ArizonaBOSS

 

[ArizonaBOSS]

I was told very early on from a Ford engineer to be careful with replacement batteries. This was specific to the 12's as the 13's weren't being made yet. My memory is a bit foggy on this but he said something along the lines of the cars being sensitive to the proper voltage.

@ArizonaBOSS

I don't remember that portion of our tour. I hope the lightweight battery going into the car soon is up to the task.

 

[Mad Hatter]

Update: went an picked up the car yesterday. On Friday night a friend pointed out a leak in the x pipe just behind the 2nd O2 sensor. This was from a stone I hit a while back. To be safe we cut out the repaired section of exhaust and welded in a new section. Right away.... No engine codes. Took the car to the track and went at it for 5 sessions and a long drive back home. Not one error code and a significant power increase. What I took as a minor leak was screwing everything up!! Shaun at AED did say that I had to get the car looked at!! He was bang on.

 

[Mad Hatter]

I fixed the P0451 code fixed today. It was the breather tube from the gas tank that got melted shut buy the rear right side exhaust. When I cut the offending piece off, the gas tank rumbled like a cows intestines for several seconds as the pressure equalized.

I got this picture from the svt forum. Looks like its a very common problem.