Not to hijack the thread but Has any body turned the filter so it sets straight up so the filter can be filled when you do a oil change ? and does it have any problems doing that ?
Also check to see if the clutch plate gap is not to large you can check it with the engine off , just use a jumper wire on the hot side and then push the clutch plate in and see if it will engage .
The caliper should not be that hard to push back in. I just use a screw driver when it is still mounted with the pads , I take the screw driver and push it between the pad and the rotor and push the pad and piston back .
The NOX is from high temp combustion the EGR and the cat are the things that keep it down , It would help if we could see all the numbers from your smog test .
The way I put my skid plate on is I added about 3/4 of inch to make the skid plate wider and redrilled the mounting holes on the passenger side so I can mout the sike plate on the bottom so if I have a fuel pump problem all I have to do is drop the sike plate and not remove the rear bumper to...