Bought a new y pipe from Davidco, nice tight fit. Put in 2 new rear senors and the front 2 are only 2 months older. Used di-electric grease in all 4 sensor plugs. Codes p0134 and p0154 still pop even after clearing the codes. Also the passenger side cat is roughly an 1/8" from the driveshaft, is that normal or is that what happens when you buy a direct bolt on? Anyone got any ideas

 

I checked the sensors on a cold start , all 4 sensors read .445 volts or something. No codes from the post cat sensors so does that possibility mean that I just need to clear the codes and drive the truck til it warms up and see if the codes still pop up or do I have another problem?

 

Probably a stupid question, but you did replace the metal gasket between the y-pipe and the manifold, right?

 

Yep the y pipe I took off didn't have one, but yeah I made sure to use the gasket on both sides.

 

if your getting 02 codes i do not think they will clear right away, i belive it time or distance for them to clear.

 

How does the wiring leading to the front sensors look and test out? I assume the upstream sensors were a direct fit without having to splice into the wiring...?

 

All the sensors was a direct fit, just had to plug them in. The rear sensors had more room to work with. But after checking the live data it appears I plugged all 4 in right, didn't know if the front two being a month older would hurt anything or not.

 

Did you torque them down to spec? The sensors that is. Also have the crush washers on them?

 

I would assume so I put the sensors on the Y before I put it on the truck. To be sure not to cross thread and I assume I torqued them enough, got them wrench tight then got maybe another full turn at least. I don't understand the crush washers part, all I used was what I had removed a total of 4 nuts from the manifold down to the y and the 2 nuts and bolts to the muffler. I also used some exhaust gasket silicone to ensure a good fit.

 

Usually they have small silver washers on them that collapse when torqued. Been a couple of years since I replaced mine, but just did my wifes on her Hyundai and they had them.