cham

That's interesting. Do you think maybe the washers were crushed so much they were kind of stuck in the rim of the converter and/or manifold? Like as if they looked apart of the converter or manifold? This is straight out of the 2002 FSM; you can see it specifies the exact alignment of the washer and mesh washer: Edit: Just found what you were talking about. On RA looks like Fel-Pro 61339 is the "Mesh Washer" and 60835 is the "Washer". I can tell based on the photos. Also looks like the Fel-Pro "Mesh Washer" does reference the correct OEM P/n. They look identical to the OEM parts found on NissanPartsDeal. Can you attest to the quality of Fel-Pro for something like this? Or should I probably leave the factory washer/gaskets alone and reuse them if they are there? And I agree, no way I'm paying $90 just for these gaskets.

@hawairish did you reuse the "washer" and "mesh washer" in the exploded diagram screenshot in my original post? Maybe replacing just that washer gasket would suffice and not the mesh?

Yeah I saw some posts of people using an electric impact in its lowest setting and being careful with great success. I might try it on inconsequential stuff first. You're right, worse case scenario I can just use hose clamps in the mean time while I order the valve cover parts. Going to try to get them from oversees since they are a fraction of the cost for OEM, just might take a while.

Noted, I want to take off that resonator/rear-cat section off anyways to see if the pre-cats have broken apart and maybe lodged pieces within the resonator. But removing the entire exhaust would be nice so I can test for leaks off the vehicle. I'll try working at the bolts when the exhaust is warm and giving the bolts heads a nice whack before unscrewing to maybe free them up. Would you advise for or against an electric impact with extensions? Also I've got some pretty bad valve cover seepage onto my exhaust manifold/cat heat shields. The VCs are the next job after this but I wanted to address the cat issue first. If lets say I shear the heat shield bolts and can't get the shields back on during re-installation, will that increase my chances of a fire hazard since the oil will be dripping right onto the exhaust manifold? So far I haven't had any smoke just burnt smell after driving.

Hey hawairish nice to talk with you again! I was planning on removing that resonator/rear cat section with the downstream O2 sensor to give room for the pre cat egress. You’re saying that’s still not enough room? Yeah I certainly am worried about shearing off those upper 6 pre-cat fasteners. If it happens on the passenger side I don’t see how there’s anyway to remove the exhaust manifold on that side haha. Ive also wondered if maybe I should give that exhaust manifold a fresh new gasket. Are our exhaust manifolds and gasket (3.5L) ever known to crack or leak? I might do a smoke test once I remove that lower resonator section just to see if I have any manifold leaks and see if it’s worth it. Curious what an exhaust shop would charge and if they’d do it right. Did you replace the studs that connect the pre-cat to the manifold or just the nuts? Sent from my iPhone using Tapatalk

Anybody have experience with removing those pre-cats? My cats are starting to choke the engine out and I can tell the engine is struggling at highway speeds. I've had P0430/420 codes intermittent for a while now. What techniques are there to make life easier? I've been soaking as many bolts as I can get to with penetrant for a good while. I'm curious if the 6 bolt heads on the upper face/side of the cat are accessed from underneath or engine bay side. I saw a video of someone removing the entire exhaust manifold and cat as a unit for the driver side; but that looks next to impossible for the passenger side. I'm willing to remove the down pipe off the bottom of the pre-cat as well so I can lower the cat down and out. The FSM diagram makes it look like the bolt heads would be accessed from underneath shown in the figure below. Also it looks like for that upper six, some of the fasteners its a stud and separate nut where as some were just bolts. I'll probably have to remove those cat heat shields first before anything can be done. My question is, can all of this be done from underneath or will I have to remove the exhaust manifold and come from the top engine bay side?

Anybody running with gutted cats without adverse effects? I'm starting to think my catalytic converters are actually failing or clogging. Besides my P0430/P0420 codes I'm still getting, according to my scanner I'm only getting about 7 misfires averages total in the past 10 drive cycles. I can't imagine that would be the source of my issues like vibration in gear at idle and lack of power. My engine consumes so much oil I do not believe replacing with new converters would solve the issue for long. Not to mention so many things cause converters to fail and apparently it can be quick. I do not have emissions testing where I live. I'm sure it will make getting rid of the vehicle much more difficult when it comes time. Anybody been in my situation before, getting at those pre-cats is difficult and to have new ones fail soon after installing would suck. I guess if I were to replace I'd go with the Magnaflow "OEM" line. Anyone gone with cheaper brands with luck?

I’d stay away from aftermarket valve covers, never heard any good things about them and I believe NissanPartsDeal has a discount right now on most parts. I’d be interested in the aluminum valve covers as long as everything works and bolts back up like factory. Can’t say I’d be super stoked about a gap like Hawairish says between the ignition coil seal and spark plug tube if using the 2002 coils with the 2001 valve cover. Obviously replacing that #1 coil with the 2001 coil seems easy enough.

Ah I see thanks Chris! The vibration basically goes away for me if I put my transmission in neutral or park at a stoplight. If you stayed in gear in 1st while at a stoplight would it vibrate and try to stall as well? Also did you have to reprogram or perform any relearn procedures when replacing the MAF sensor? Sent from my iPhone using Tapatalk

I gotcha. I think I might replace the IACV for the hell of it next time I go in to replace my valve covers. See if I get any results. Just to be clear, you were having a full vehicle vibration at stoplights in gear once the engine is warm? It would go away in park and neutral? What is this ABS issue you were talking about? Were you saying that might have something to do with the RPM sag and vibration in gear? Sent from my iPhone using Tapatalk

Thanks for the update CamperDan, let us know if the problem comes back or not. I’ve been monitoring my g/s and it’s at about 3.6-3.7 at idle warmed up. Sounds like it’s good and I have been cleaning it over the years. Correct me if I’m wrong though, you replaced your idle air control valve at one point correct? Do you remember it fixing any vibration or stumbling back then? Also did you use oem factory MAF sensor? Sent from my iPhone using Tapatalk

I'll be patiently waiting for the results, thanks for keeping us updated! Just got a new smoke machine so in a couple days I'm going to be very thorough finding any intake or exhaust leaks. Thought about testing EVAP leaks as well but I've got to get a handle on purge solenoids and lines first as I'm sure some areas are supposed to purge smoke. Also because my tailpipe has fallen apart (can't get a great seal when smoking) it's almost better to find leaks by looking for liquid condensation forming after you start up a cold engine.

Gotcha, fleurys in another thread titled "Random Misfire Help!" mentioned being able to read misfire count with an OBD2 scanner but did not mention the one he uses. I'll ask the guys at Nisscan if its possible, regardless I'd imagine NDS II will come in handy for other things. I might have misspoke. When I said butterfly valves I meant those lower intake power valves that famously eject screws. Is there a another set below them or just the one set?

Hey [mention=36148]hawairish[/mention] can you read “misfire count” through mode 6 for individual cylinders in NDS II. Also what year is your Pathy? Looks like Bluedriver’s mode 6 is pretty limited. Need to figure out what the TID codes mean but it only lists pass or fail. Sent from my iPhone using Tapatalk

Here is the linkage for the vacuum actuator of the butterfly valves. The red circle shows where you can move that link to open the valves I believe. Sent from my iPhone using Tapatalk