88pathoffroad Posted May 3, 2005 Share Posted May 3, 2005 I finally got around to cleaning off the MAF sensor with Q-tips and alcohol, put it back on. Then I took out my O2 sensor and used a propane torch to burn off the carbon deposits. (Be careful not to overheat the sensor, it CAN be ruined that way.) Before this, I normally got 11-12 MPG. First tank of gas after that, I got 14.7. This last tank, I got 16.6. Whoa. I've NEVER gotten 16! And I've owned my Pathy for more than five years now. Go figure. I guess when parts are clean and working properly, you get better power and gas mileage, eh? I do notice a little more power, it doesn't smell like raw gas or like it's running rich every now and then, and it starts and idles NOTICEABLY better now. I'd reccommend doing this for anyone that's getting poor mileage, it takes but a little while and has such great benefits. Link to comment Share on other sites More sharing options...
Guest vERSATILE Posted May 3, 2005 Share Posted May 3, 2005 I finally got around to cleaning off the MAF sensor with Q-tips and alcohol, put it back on. Then I took out my O2 sensor and used a propane torch to burn off the carbon deposits. (Be careful not to overheat the sensor, it CAN be ruined that way.) Before this, I normally got 11-12 MPG. First tank of gas after that, I got 14.7. This last tank, I got 16.6. Whoa. I've NEVER gotten 16! And I've owned my Pathy for more than five years now. Go figure. I guess when parts are clean and working properly, you get better power and gas mileage, eh? I do notice a little more power, it doesn't smell like raw gas or like it's running rich every now and then, and it starts and idles NOTICEABLY better now. I'd reccommend doing this for anyone that's getting poor mileage, it takes but a little while and has such great benefits. how do i identify the maf air sensor? Link to comment Share on other sites More sharing options...
fastskier Posted May 4, 2005 Share Posted May 4, 2005 Cool - I have to do this. I've looked for my oxygen sensor though and I haven't been able to find it - it should be screwed into the exhaust manifold with wires coming out if it ?? I also too would like a refresher of where my MAF is - I thought they were on the downstream side of the air filter?? Thanks Link to comment Share on other sites More sharing options...
jdub Posted May 4, 2005 Share Posted May 4, 2005 Yes, detailed directions would be great 88. My mileage has just started to go down the crapper. 200 miles a tank now. Has newer plugs, cap & rotor. And is running a little rich. Link to comment Share on other sites More sharing options...
robinasu Posted May 4, 2005 Share Posted May 4, 2005 I finally got around to cleaning off the MAF sensor with Q-tips and alcohol, put it back on. Then I took out my O2 sensor and used a propane torch to burn off the carbon deposits. (Be careful not to overheat the sensor, it CAN be ruined that way.) Before this, I normally got 11-12 MPG. First tank of gas after that, I got 14.7. This last tank, I got 16.6. Whoa. I've NEVER gotten 16! And I've owned my Pathy for more than five years now. Go figure. I guess when parts are clean and working properly, you get better power and gas mileage, eh? I do notice a little more power, it doesn't smell like raw gas or like it's running rich every now and then, and it starts and idles NOTICEABLY better now. I'd reccommend doing this for anyone that's getting poor mileage, it takes but a little while and has such great benefits. I have been wondering how much the O2 sensor could be affecting my mileage - it is original. I need to clean my MAF too. Is the MAF easy to take out? I forget what holds it on the side of the throttle body. Link to comment Share on other sites More sharing options...
88pathoffroad Posted May 5, 2005 Author Share Posted May 5, 2005 These instructions are for a 86.5-89 with the VG30i: The MAF sensor is on the driver's side of the TBI under the air cleaner. It has three screws holding it on. Unplug the wiring harness first, then unscrew the screws and pull the sensor directly outward. It has a stem that projects about 1.25" into the TBI, be careful not to damage the heater wires on the tip of the MAF sensor or you'll need a new one. These heater wires are what makes the dammn thing work. Now, clean the little wires and the entire tip very carefully with Q-tips soaked in rubbing alcohol, then put the sensor back on. Done! These instructions are for any Pathy: The O2 sensor is located under the driver's seat on the main exhaust pipe after the y-pipe, pointing upwards and toward the passenger's side. It has three wires coming out of it that go up over the transmission and over to the passenger's side. Mine took a 18mm wrench to get it off. You can remove it without unplugging it if you're careful to not twist the hell out of the wires. After it's unscrewed, let it hang down under your Pathy and use the propane torch to heat the tip of the sensor. Just heat it until it glows red-hot and the blue propane flame turns reddish-orange behind the sensor. Then let it cool off a sec and hit it from another angle. Don't overheat the sensor or cook the threads, you may end up with a ruined $135 sensor. After that, let the sensor cool and eyeball it. Does the surface of the metal look clean and free of deposits? If so, you're done. If not, hit again until all the carbon burns off. Let the sensor cool. Then apply some fresh anti-sieze compound to the threads and twist the wiring up opposite of the direction that you will be screwing it in. Screw it in, reset your ECU by unplugging the "ECCS" fuse for 30 seconds, then start as usual. Let us know how it goes! Link to comment Share on other sites More sharing options...
flnl Posted May 5, 2005 Share Posted May 5, 2005 Gonna sound foolish but... What are Q-tips??? Link to comment Share on other sites More sharing options...
flnl Posted May 5, 2005 Share Posted May 5, 2005 (edited) OOOOPPSSS! :X I got it! Hehehe (http://www.qtips.com/) You mean "cottonetes" Strangers...... Edited May 5, 2005 by flnl Link to comment Share on other sites More sharing options...
Precise1 Posted May 5, 2005 Share Posted May 5, 2005 Just have to pass this on; something I learned from mold work... Regular Q-tips have some glue that holds the cotton (or whatever it is) on. This glue disolves in chemicals including isopropyl alcohol and will leave a residue. Maybe it doesn't apply in this circumstance; maybe the MAF sensor just burns it off or doesn't care... A final wipe with a lab grade swab or tissue couldn't hurt... B Link to comment Share on other sites More sharing options...
fastskier Posted May 5, 2005 Share Posted May 5, 2005 Cleaned my MAF sensor tonight on my 94. Pretty easy. Its basically bolted right on to the back of the air cleaner box. Its a thin black rectangular box bolted to an aluminum manifold. Two screws (phillips) to get it off - the bottom one is a little tight to get to. And like 88 says be carefull taking it out - pretty fragile. Thanks for the info on the O2 sensor, I'll tackle that next. Link to comment Share on other sites More sharing options...
DJ Dank Posted May 6, 2005 Share Posted May 6, 2005 I'll have to give that a try. Thanks for the tip 88! Link to comment Share on other sites More sharing options...
Guest Skweaks Posted May 7, 2005 Share Posted May 7, 2005 Just got back from cleaning the oxygen sensor and it runs great! After I got to the MAF sensor and cleaned that, the engine now runs real ruff around 1500rpm and annoyingly rough when in gear with the brake on... Any ideas as to what it could be? ...maybe the glue off the Q-tips??? Link to comment Share on other sites More sharing options...
88pathoffroad Posted May 7, 2005 Author Share Posted May 7, 2005 Check the MAF sensor wiring plug and make sure there are no air leaks anywhere after the sensor. Link to comment Share on other sites More sharing options...
fastskier Posted May 7, 2005 Share Posted May 7, 2005 how are you guys removing your O2 sensors? Mine (94) has never been removed that I know of and is rusted in pretty well. I tried putting a wrench on it and smacking it with a hammer but I am afraid of breaking something. I let some liquid wrench soak in it overnight so I will try that but any tips would be appreciated. Link to comment Share on other sites More sharing options...
94extreme Posted May 7, 2005 Share Posted May 7, 2005 check this out for more ideas on increasing your truck's mpgs.. Link to comment Share on other sites More sharing options...
DJ Dank Posted May 7, 2005 Share Posted May 7, 2005 Anyone have a pic of the 02 sensor? So I Know what I"m looking for? Link to comment Share on other sites More sharing options...
flnl Posted May 8, 2005 Share Posted May 8, 2005 (edited) Anyone have a pic of the 02 sensor? So I Know what I"m looking for? http://www.rockauto.com/ref/SMP/SMPDetail2.html?SG351.jpg http://www.Nissan-techinfo.com/Nissan/refg...thfinder/fe.pdf pages 9 to 12 Edited May 8, 2005 by flnl Link to comment Share on other sites More sharing options...
jonathanjdfraser Posted May 8, 2005 Share Posted May 8, 2005 hey Skweaks, when i cleaned my MAF sensor a few months ago, i put it back in and started the truck, it went right up to 4 grand and stayed there, lol, so i took it out again and just blew on it, didn't touch it, put it back in, works excellent. Link to comment Share on other sites More sharing options...
fastskier Posted May 18, 2005 Share Posted May 18, 2005 so no one who has removed their O2 sensor can tell how they did it? I plan to take a torch to the exhaust when its cold, heat up the pipe and try to get the O2 sensor off quick. Opinions? Link to comment Share on other sites More sharing options...
NZ Terrano Owner Posted May 18, 2005 Share Posted May 18, 2005 Just had a look under my truck and no sign of the sensor on the exhaust. I have a '95, 2.7Turbo Diesel. Are these sensors just on the petrol engines? Are they for your emission regulations? Cheers Al Link to comment Share on other sites More sharing options...
88pathoffroad Posted May 19, 2005 Author Share Posted May 19, 2005 Diesel engines don't have o2 sensors, no. Mine came loose with a regular wrench, but it's a PITA to get your hands in there. Link to comment Share on other sites More sharing options...
mws Posted May 20, 2005 Share Posted May 20, 2005 Pulling O2 sensor? I also got lucky - mine came loose with just an end wrench as well. Tips: Douse the threads with PB Blaster for 3 or 4 days before trying. Do heat the pipe and bung with propane torch. DOn't heat the sensor. Give the bung a few sharp raps with a hammer to dislodge rust. Try with wrench , but no gorilla efforts. If really tight, use a 6 point socket, and only a 6 point socket. 12 point will only round it off and you'll have to revert to pipe wrench or vice grips. Most tool shops will sell a special O2 sensor socket with a slot cut in the side to let the wires come out. The other option is to cut the wires and use a regular 6 point socket. Cut the wires at least an inch away from senson so you can splice back together if you fail to get it out. Link to comment Share on other sites More sharing options...
M in KC Posted June 13, 2005 Share Posted June 13, 2005 I did the MAF sensor cleaning thing this weekend. For those of you have done theirs, did you see much gunk on yours? Mine looked whistle clean except for some grey deposits on the posts holding the wires. Just curious. I'll fill 'er up and see if I made any improvements. Mike Link to comment Share on other sites More sharing options...
Ramithepimp77 Posted June 22, 2005 Share Posted June 22, 2005 I just cleaned my MAF and it was KINDA dirty nothing TOOOOO bad but after I got it all back together it seems like I feel a diff in power already. Ill be filling up the gas tank tomorrow so I wont be able to tell ya what the gas mileage is like YET. Thanks Aaron! Rami Link to comment Share on other sites More sharing options...
nige Posted August 20, 2005 Share Posted August 20, 2005 I just unscrewed mine and it the little resistor looking thingies are nice and silver with an opaque case. All four of the prongs supporting those are nice and silver. Is that what they look like when they're clean? Link to comment Share on other sites More sharing options...
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