codes after obx long tube onstall

[99expo54]

Hey all, new to the site. Installed Obx long tubes onto my 99 expo with the 5.4 two weeks ago. These are no cats with this setup I have. Y pipe runs into a single on dual out muffler, then 2.5" dials out the back. Ever since I installed these I'm getting codes p0135 p1132 and p1151. I can clear them and within ten minutes they pop up again. Truck Idles strange, randomly seems like its gonna die then revs back up and Idles fine. Used an entire tank of gas in the last 155 miles. Anybody else experience this problem after installing headers?

 

[1997SCEBFEX]

Welcome.

Sure your ecu is trying to figure out what the heck is going on. Big change in back pressure and no cats will make it run rough for sure.

sure others will chime in.

post a pic of your rig.

PanHandler.

 

[FordandPolaris]

P0135 - O2 sensor heater circuit malfunction
P1132 - Fuel air mix off I think (Google was not very clear on that one)
P1151 - Also fuel air mix code

I would bet it is the upstream O2 sensors if I had to start somewhere. They control tuning for the engine, if they are factory original I would replace them. If you removed them because of removing the cats and manifolds, you need to either put in dummy sensors (if I think of their technical name, I will post it back, they are escaping me at the moment) or you need to install O2 sensors back into the system. These are essential.

 

[toms89]

Hey all, new to the site. Installed Obx long tubes onto my 99 expo with the 5.4 two weeks ago. These are no cats with this setup I have. Y pipe runs into a single on dual out muffler, then 2.5" dials out the back. Ever since I installed these I'm getting codes p0135 p1132 and p1151. I can clear them and within ten minutes they pop up again. Truck Idles strange, randomly seems like its gonna die then revs back up and Idles fine. Used an entire tank of gas in the last 155 miles. Anybody else experience this problem after installing headers?

Your front O2's are not working properly. I assume you reconnected your front O2's. The PCM uses these to adjust the fuel trims.

You may need a custom tune to increase the entire O2 delay table because with long tubes this time increases dramatically. You may also need to extend the O2 heater on time because they may run cooler due to the extra cooling surface and distance away from the cylinder.

Not sure how you extended the O2 sensor wires but you need to use extensions. It is said not to splice in the the O2's sensors wiring because it gets outside O2 it needs to function properly via the wire?!

 

[toms89]

P0135 - O2 sensor heater circuit malfunction
P1132 - Fuel air mix off I think (Google was not very clear on that one)
P1151 - Also fuel air mix code

I would bet it is the upstream O2 sensors if I had to start somewhere. They control tuning for the engine, if they are factory original I would replace them.

The latter two codes means the O2s are not "toggling" properly. (rich/lean)

Stock O2's are narrow band. They must toggle between rich and lean constantly to find stoich. They have no idea how rich or lean it is running only that it is.... Hope this make sense. Wide band sensor tells exact air/fuel ratio. Narrow band knows rich or lean from stoich (14.64 to 1 with straight gasoline) But not by how much so PCM constantly toggles back and forth across stoich to know where it is...

 

[GAINMOB]

welcome to the site

 

[99expo54]

P0135 - O2 sensor heater circuit malfunction
P1132 - Fuel air mix off I think (Google was not very clear on that one)
P1151 - Also fuel air mix code

I would bet it is the upstream O2 sensors if I had to start somewhere. They control tuning for the engine, if they are factory original I would replace them. If you removed them because of removing the cats and manifolds, you need to either put in dummy sensors (if I think of their technical name, I will post it back, they are escaping me at the moment) or you need to install O2 sensors back into the system. These are essential.

I still have all 4 02's in the system. The front ones would reach to connect them so I cut the wires and extended them about 10".

 

[99expo54]

The latter two codes means the O2s are not "toggling" properly. (rich/lean)

Stock O2's are narrow band. They must toggle between rich and lean constantly to find stoich. They have no idea how rich or lean it is running only that it is.... Hope this make sense. Wide band sensor tells exact air/fuel ratio. Narrow band knows rich or lean from stoich (14.64 to 1 with straight gasoline) But not by how much so PCM constantly toggles back and forth across stoich...

So I should try running wide band 02's?

 

[toms89]

So I should try running wide band 02's?

No.

You cannot because the hardware is not set up for it. Just mentioned it for comparisons sake and to give you an idea how the pcm uses the stock O2's. Many tuners install widebands to monitor air/fuel ratio independent of the pcm.

Did you splice the O2 sensor wiring or the harness?

 

[99expo54]

No.

You cannot because the hardware is not set up for it. Just mentioned it for comparisons sake and to give you an idea how the pcm uses the stock O2's. Many tuners install widebands to monitor air/fuel ratio independent of the pcm.

Did you splice the O2 sensor wiring or the harness?

I splice the sensor wiring. I know they sell 02 sensor extension wiring; how is this any different?

 

[toms89]

I splice the sensor wiring. I know they sell 02 sensor extension wiring; how is this any different?

I have seen many warnings not to splice the sensor wiring because it uses the wires leading into the sensor to get outside O2 to operate properly. If you splice it you interrupt this. If I can find it I will post it but it may have been in my tuning manuals..

 

[01yellerCobra]

My first set of O2's I spliced in extra wire. But I soldered it and used heat shrink. I never had a problem. When I put in new sensors with the headers I went with extenders because I was lazy and the extenders were much easier.

But like Tom said, you need a tune for the headers. I had to extend my transport delay and my heater duty cycle about 15% for things to work correctly.

 

[99expo54]

My first set of O2's I spliced in extra wire. But I soldered it and used heat shrink. I never had a problem. When I put in new sensors with the headers I went with extenders because I was lazy and the extenders were much easier.

But like Tom said, you need a tune for the headers. I had to extend my transport delay and my heater duty cycle about 15% for things to work correctly.

Was kinda expecting that I needed a custom tune. Was hoping for a cheaper way out. What the best way for a custom tune? Find a tuning shop? What's the average cost of a tune?

 

[toms89]

This specifically was from a ford tuning manual but have seen it elsewhere as well. It happens to mention the other items also but note last paragraph.




See...not making this stuff up.. lol

 

[99expo54]

This specifically was from a ford tuning manual but have seen it elsewhere as well. It happens to mention the other items also but note last paragraph.




See...not making this stuff up.. lol

Interesting.. so I need new upstream sensors, and pick up the extension wiring also. No big deal. Maybe I will get lucky and this will solve my issues.

 

[toms89]

Its likely a combination of all the above. O2 sensor delay, sensor heat (need to be 600 degrees to operate properly), and cutting the sensor wires.

 

[99expo54]

Its likely a combination of all the above. O2 sensor delay, sensor heat (need to be 600 degrees to operate properly), and cutting the sensor wires.

I've searched the web looking for a tuning shop in Wisconsin, and cannot find anything. Can I get a custom tune wrote for my hypertech power programmer? I used the hypertech last night and changed the tune from 87 to 93 octane and it is running much better. Truck has been running 45 min without throwing any codes. When I spliced the wiring I didn't cut off any of the sensor wiring, just the plug then extended it. Can I remove the extra wire, solder the plug back on, then get extension harnesses?

 

[99expo54]

Just threw all 3 codes again, plus code p1152

 

[toms89]

Some of the codes indicate a possible short or open circuit on your O2 sensor heaters!! Double check your wiring!!

But you may need custom tune!! I purchase a sct 3000 for my custom tunes with my lightning conversion.

SCT Performance - SCT X3 Power Flash Ford Programmer**Part Number: 3000

It was initially set up and tuned by JJ @ Woodbine Motorsports. Warning!! Turn volume down before you click on the link...lol.

Home Page

If you purchase the SCT through JJ @ Woodbine Motorsports he can write and email you a custom tune. His prices are reasonable. He can also dial it in via datalogging and email.

There is also our local vender.. 5 Star Tuning. But I have no personal experience with them.

 

[Expyguru]

I spliced my front O2 sensors no problem, just make sure you dont try to butt splice them. they have to be soldered and wrapped with heat shrink and then a fiberglass silicon wrap to keep heat off wires.