RCWD21

Ok cool. I read on some of their stuff but wasn't 100% sure. I'm guessing as close to the original spot as possible would be best since it operates based on perceived frequency changes? Ill be replacing it once I get the oxygen sensor in and can test it. Would the knock sensor cause this bad of a drop in mileage? Everywhere I've read said it would only be a few mpg if that.

I have an ntk sensor on its way, it should be here the 25th. I don't like cutting and splicing sensors in. This is the sensor to the plug. It tests good but I'm going to replace it since its the original sensor in there.the only code I'm getting is for a knock sensor so I'm oreding one of those today. And now I have a question about that. Can I mount the knock sensor somewhere else? Like on the intake plenum?

Ok, well it starts and runs again. The fix? Threaten to replace the starter relay and magically it fixes itself. Hasn't given me one issue since I put the pare relay in the glove box lol as for the o2 sensor I'm still looking for a good price of an NGK brand. I looked at it today and sprayed some penetrating oil on it right after I drove it a little bit. Upon getting some more crud off of it I discovered its the original Nissan sensor and seeing as its 25 years old I'm just going to replace it to eliminate it as a variable. Also I drained the tank bone dry pulled the fuel pump fuse and left the key on and put in 5.25 gallons at a time and the fuel gauge is dead on accurate at each interval. That's about all I'm able to do for now because my work space is currently taken up by a 200sx that I'm servicing and installing a timing kit and brand new valves.

I can't remove it without removing the transmission lines. I went through this when I rebuilt the transmission. The lines and the passenger side axle get in my way. But I'm going to try the relay and a booster battery and see if that fixes my problem first

Removing the starter on these is a pita. Especially with cooling lines right in the way

I tried that already and nothing. I don't get anything from the starter. I have another relay here I'm going to try plus another battery justvto eliminate the variables

Just wanted to update. I haven't been able to test it et because for some reason either the starter or the relay has decided to go bad on me. I get a click but nothing more. I hope its just the relay

I set mone with a digital ohm meter but it could still have a dead spot somewhere in there

I'm in North Carolina, I don't have to pass emmisions. I'll test it tomorrow at the shop so I can also try to remove it if its bad. But on a different note what else could it be if the sensor is good and working correctly? I've double checked all wiring and it all checks out. I set ignition timing when I did the major servicing when it was on the stand. Could a bad TPS also cause symptoms like a bad o2 sensor?

Would it matter if the sensor is further upstream? Or does it need to be close to the cat?

I just don't want to snap it off or break the bung. Everything from the cat to the very end is welded together and I don't have the money to replace all the pieces like I'd want to. Let me put the rust thing into perspective if I can, there's so much rust that when I tried to remove it the first time the bung twisted the tubing so I left it alone. Plus its mounted on the upward side around 1 O'Clock and not closer to the side like its supposed to be. I'll try and post pics of this hack job that is currently my exhaust system later

Ok thanks guys! I'm gonna look into getting a new sensor first then try to get the old one out. Hopefully it breaks free and screws out like it should

I'll spray it down with penetrating oil and get it hot and try and take it out again. If I break it off I have to replace everything from the Y pipe back because someone stupidly welded EVERYTHING from the cat back. They even put the muffler in with the weep hole on the top side. Not to mention the cat rubs against my crossmemeber and the rear hump by the axle is wrong and when I hit a bump it slams into the rear suspension so I have to baby it when I drive...

Its not in power mode. Both modes work and I can achieve torque converter lock up but at slower constant speeds between 40/45 it fluctuates but I may try that lock up switch method to see if it will help resolve that issue.

Sorry about only replying to this now guys. I'm still getting used to this forum setup. I've cleaned the contacts and checked and cleaned all the grounds on this rig. Even installed extra grounds. I haven't run my tank low in a while but I'm thinking of slowly running the tank low by draining it and letting the float drop with the level all the way til the tank is empty to see if the light will come on. The bulb is good and everything has the proper continuity but the damn light just won't come on. I'm going to be switching clusters to one of the ones from a hardbody. I like the layout and coloration better anyways.

I'll try bumping it up to 30psi. But it got better gas mileage BEFORE I did all this work. Why would this be? This is really wracking my brain.

Yes. I've gone 20 miles at 55mph with a GPS active from start to finish and its accurate with multiple GPS devices

If you have any other questions feel free to ask. I'm really just hoping its just a faulty gauge. I have another sending unit out of a 96 hardbody that I was thinking about swapping in if the wiring is the same just to see if it made a difference

I'd like atleast 14 to 17mpg. I run Goodyear wrangler radials 235 75 15 I think, at 26psi. Air filter is new and every inch of the intake system is clean and free of obstructions. Oil is fresh and still golden stock ride height. Alignment is correct. I get my fuel from the shell station. 87 octane. No vacuum leaks all new gaskets and seals exept for the head gaskets. Everything engine wise is up to spec. All belts and fluids are new. I drove it from norfolk Virginia to Morehead city north carolina at an average speed of 75mph. I left with a full tank and had maybe an 1/8 once I got home. The gauge didn't work when I got it but I cleaned the contact on the sending unit and it works reliably now. I realize this being 4x4 and being as heavy as it is its not going to get fantastic mileage but ibwould like it to be as best as possible.

Thats literally the only thing I haven't replaced yet. Mainly because it looks like if I remove it its going to destroy the threads in the bung. I checked my ecm and I get code 55. I'll try the other mode where it monitors the sensor but is there also a way for mW to check it with a multimeter while its running? I can make a harness adapter for it no problem.

1990 Nissan pathfinder. Vg30e. Recent major tune up and rebuilt transmission with aftermarket cooler. I get great gas mileage around town in pretty moderate stop and go traffic with a speedlimit between 25 and 45mph. But when I drive 45 miles over to Jacksonville and back (90mile round trip) I burn almost a half a tank. I only went over 3k rpm shifting a few times when there was a lot if traffic behind me. Other then me and my 2 friends there wasn't that much weight in the vehicle. Everytgingnis set to spec according the the FSM. Does anyone have any idea what's going on? I've never experienced this and I've owned several Nissans. PLEASE HELP!

Ok guys this is my first post so please take it easy on me. I've been following along on this forum for about a year now but finally decided to join since I recently got a 1990 pathy. Well a long story short is that after 3 months of owning it this is the 7th or 8th day total that I've driven it. I rebuilt the transmission and did major maintenance to the engine which I'm surprised even ran when I took it out. It came from Panama of all places and I live in North Carolina.but thats another story. Why I'm here is that even though I've cleaned the contacts and replaced the bulb and checked all the wiring and even tried switching sending units I still cannot manage to get the low fuel light to come on. Everything checks out by the book bit it won't work to save its life. I've even ran out of gas but that was when the qauge was reading inaccurately but I fixed that issue already. Any idea as to what else it could be? I've traced every wire from from to back and cleaned all contacts and checked for grounded and shorted wires. I'm at a loss and its really annoying seeing the icon there but knowing the light doesn't want to work when it should. Thanks in advance. Oh and by the way I've searched and searched but its nothing like what I could find on here.