Mrt Catted H-pipe Help - 2003-04 Mach 1 Registry Owners Club

Marines_Mach1 · 10-17-2004, 06:47 PM

I recently purchased a MRT Cat H-Pipe and when it was installed they cross-threaded one of the 02 sensors. Service Engine light came on and took it to get looked at and now that 02 sensor is bad. Cant replace it b/c the mech was scared of removing it and stripping the threads of the h-pipe. Its the driver's side front sensor, what can I do to get that service engine light off????

Mach1 w/Shaker · 10-17-2004, 07:08 PM

Did it just start or did it happen as soon as you had the pipe changed? If it just started try disconnecting the battery for a couple of hours and hit the brake to drain the juice out of the computer. Then reconnect, start and let idle for 15-20 minutes before driving and see if it clears the SES light. The biggest problem is that it occured on the front sensor where the ECM makes A/F adjustments. If it had been the back one you could turn the light off with a mil eliminator. The only thing I can think to do is have the shop that crossthreaded the sensor pay to have a new sesnor bung welded into the pipe and a new O2 Sensor. Hope it works out for you.

I just went back and reread your description and it sounds like the light came on immediately if so I think your going to have to replace the bung and sensor. Good luck.

goebbelj@hotmai · 10-17-2004, 08:53 PM

I kept flipping the same code with the MRT H-pipe. Bank 2 Sensor 1. I replaced the sensors to see if that would fix it.....It didn't.

I kept moving the sensors around when the same code would flip. This would fix it for about 900 mile then flip again.

Recently, I have downloaded diablo's latest rev 50b program onto my tuner, and turned off the rear o2 sensors. Plus, richened the fuel ratio from 2-4K by 9.5% (I know its lean). The code has not reoccured yet, but its only been 300 miles.

I would take the sensor out if you think it is bad. If you ruin the bung you can get a new one welded in. You can try rethreading the old bung with a tap to see if it will still work for you.

Last thing, pulling the battery cables will clear the code, but if the problem is still there it will flip again. Do what ya gotta do.:THUMBSUP:

10-17-2004, 06:47 PM	#1
Marines_Mach1 Registered User Join Date: Jun 2004 Location: Ft Worth,Tx Posts: 22	Mrt Catted H-pipe Help I recently purchased a MRT Cat H-Pipe and when it was installed they cross-threaded one of the 02 sensors. Service Engine light came on and took it to get looked at and now that 02 sensor is bad. Cant replace it b/c the mech was scared of removing it and stripping the threads of the h-pipe. Its the driver's side front sensor, what can I do to get that service engine light off????

10-17-2004, 07:08 PM	#2
Mach1 w/Shaker Don Ron de Mach-O Join Date: Oct 2002 Location: Fort Worth TX Posts: 1,345	Did it just start or did it happen as soon as you had the pipe changed? If it just started try disconnecting the battery for a couple of hours and hit the brake to drain the juice out of the computer. Then reconnect, start and let idle for 15-20 minutes before driving and see if it clears the SES light. The biggest problem is that it occured on the front sensor where the ECM makes A/F adjustments. If it had been the back one you could turn the light off with a mil eliminator. The only thing I can think to do is have the shop that crossthreaded the sensor pay to have a new sesnor bung welded into the pipe and a new O2 Sensor. Hope it works out for you. I just went back and reread your description and it sounds like the light came on immediately if so I think your going to have to replace the bung and sensor. Good luck. __________________ Ron T.: 2004 Texas Bullitt/Mach1 Shootout Slowest Mach1 Award Winner Founder and President of the lisaz28 Fan Club (Establshed Jan. 2004) 1969 Calypso Coral Mach 1 Now champagne gold 2003 Torch Red Mach 1 5-Speed & IUP Born on Feb. 8 2003 Gone but not forgotten Last edited by Mach1 w/Shaker; 10-17-2004 at 07:24 PM.

10-17-2004, 08:53 PM	#3
goebbelj@hotmai Mach 1 Driver Join Date: Aug 2003 Location: Prior Lake, MN Posts: 889	I kept flipping the same code with the MRT H-pipe. Bank 2 Sensor 1. I replaced the sensors to see if that would fix it.....It didn't. I kept moving the sensors around when the same code would flip. This would fix it for about 900 mile then flip again. Recently, I have downloaded diablo's latest rev 50b program onto my tuner, and turned off the rear o2 sensors. Plus, richened the fuel ratio from 2-4K by 9.5% (I know its lean). The code has not reoccured yet, but its only been 300 miles. I would take the sensor out if you think it is bad. If you ruin the bung you can get a new one welded in. You can try rethreading the old bung with a tap to see if it will still work for you. Last thing, pulling the battery cables will clear the code, but if the problem is still there it will flip again. Do what ya gotta do.:THUMBSUP:

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