wcm s2k fuel cut with new exhaust

[wcmgoldie]

I had new exhaust made for my car a few days ago and ever since it has been sputtering and bucking after about 5000 PRM on a straight away with a full tank of gas. The original exhaust set up had a cat and two 02 sensors. I was told without a cat only the front 02 sensor was needed. The exhaust now has a single 02 sensor just after the collector with no cat. I told the guy who made it to leave the front 02 sensor but should it be the rear 02 sensor that is really needed? Does the distance of the o2 sensor from the collector matter? It is currently just a few inches past the merge inside the engine bay. It is possible it could be a fuel system problem but i was only having fuel cut problems with a low tank and only during cornering since i have no fuel cell foam. does anyone know if the two 02 sensors are the same and interchangeable? The 02 sensor that wasn't being used was left coiled up in the engine bay. After i noticed fuel cut issues i unplugged it and had the same problem. Would it make sense trying to plug the o2 sensor being used into the other plug from the 02 sensor that is no longer used? Its not really an area i'm too good with and didn't want to keep leaning it out, ruining the motor.

[Mondo]

Loren will probably be by soon with a definitive answer...

When I changed from the stock ECM to the AEM stand alone unit, we eliminated the rear sensor. No problems.

Stock may require it.

[WestTexasS2K]

Maybe the two sensors got swapped. It should run on just the primary one. Try swapping to the other sensor, and see what happens. Make sure the engine is warmed up good. It will not go into vtec if the engine isn't up to tempature.

[wcmgoldie]

I switched the 02 sensors and the car was having the same fuel cut problem. It ran the same with either 02 sensor. The serial numbers are: the Spare: 508-H1

Sensor being Used 613-H1. I'm not sure which sensor should really be used. That would be helpful too. The 508 sensor the wires were all spliced back together and some splices were even broken so I put it back together the best I could before driving with it.

[wcmgoldie]

Roman was saying that his car is using the o2 sensor that is on the long division off the harness. Mine is now using the one on the short division that only comes about 2" off the harness. The sensors can't be changed from plug to plug because when you take them apart one plug is male and one is female which you can't tell until apart. I just wanted to make sure I have the right sensor in before I look further. Even though when either sensor was used the car was having fuel cut. I changed the low pressure fuel filter which I thoigh may have been the issue since it had a moderate amount of foam in it. I think my system has two filters, low and high pressure and two pumps. That it what I was told anyway. I didn't look too far into it. The low pressure filter is first after the tank and I would think it would catch everything.

[Blindcars]

Speacking of exchaust systems it is coming up soon on the fabrication lost as i will soon have a hood and can finalize setting the engine. So what double skinned muffler are most using on the WCM Ultralight? I dont want a single skin as i dont want flesh left on the muffler . What size inlet and outlet?

 

Thanks

Leo

[RGTorque]

my car has a flowmaster which i LOVE. good sound, NOT extremely loud!

Edited October 7, 2014 by RGTorque

[wcmgoldie]

I had mine made 1-7/8 primary with a band clamp connected to 3" stainless. The muffler is a 3" i/0 glasspack I think. It's pretty loud but sounds amazing. The fuel cut issue I had was a clogged fuel fitting. Runs better than ever now. I'm glad to get rid if the fuel cell foam.