Thread: Year long problem solved!!!

Okay so check this. A year ago my VE was swaped in my 99 Sentra SE-L. When the swap was complete the car hauled ass. I loved it but within about 2 months after the swap I started getting a very random miss fire. It sucked so bad and no check engine light was present. I continued to drive and started to notice that the car would shutter and on occasion buck at normal cruising speed. Each time this happened it would only happen for literally a second maybe two. As more time past it started acting real bad when it was moist out. At this point I knew it was electrical. Guys I back pined the whole ECU circuit. NOTHING. Beyond frustrated and the car was only getting worse as time went on. Next thing I knew it was no longer just a miss fire but something bringing my cars cruising speed of 80 MPH down to 70 MPH with my foot in a steady position. I changed my cap and rotor, plugs, wires, and they were not the fix even thought they all needed replacement. I decided it was a fuel issue. Well injectors, fuel pump relay, fuel lines, filter, and pump all checked out. MAF was also replaced because it crapped out but was still not the fix. Checked TPS too. Still no check engine light. I finally asked myself what else is related to fuel and it hit me check the 02 sensors. But I said to myself they were both brand new when swap was done. How could they be it? Well the first one I looked at was the one at my headers that has always been close to the fan blades. Still looked ok and electrically checked out until I looked very close. The wires on this O2 sensor were barely worn but were. I could see the fan blades had hit it before. I decided to back pin terminal 46 on the ECU with my DMM and sure enough while driving I felt a shutter and right before my eyes I saw that multi meter go from .5 V to 14 V. For those who don't know, O2 sensors only play up to 1V max and this was bad voodoo. I realized that this was my problem. A nasty RANDOM short to power on my front heated O2 sensor. Let me tell you guys it has been an adventure but I am glad it is over. I feel like I am finally going to be able to experience this swap for what it was meant to be FUN!. Hope this helps those with problems like this. I searched both forums and all I ever saw was reground the MAF. I have learned to look twice. That sensor always looked like it cleared the fans. Guess not, slim fans are being ordered tonight. Good luck guys and happy diagnosing!

Truly amazing. Good job finding that nasty gremlin! Always good to hear something like this.

^^^^Just a suggestion.

Congrats on the fix.

Congrats on the fix.
Did you get out the stripped allen bolt?

great when ppl give feed back on problems they encountered

No I have not had the time to tear into her again to do the valve springs. I got a job with Toyota in Baton Rouge LA and as soon as I have the time I am going to extract it and put them in. Toyota will be interesting because I wanted Nissan but they said they could transfer me later if I wanted. Has been great since I fixed O2. I like the N1s they just keep pulling.

On that note I must say I have 2 of 4 things coming my way in order for me to be able to get in project car mode lol. 1 more money 2 a garage. The next two are I need another daily driver and my girls patience but I think I am good she is pretty dam cool. Where I will take the VE should be interesting.

thats funny cause thats about the same problem I have on my now, random missfires and bucking... one of the fans did hit the wire, however only the shield was ripped but no exposed wires... Now i will check it out for sure. GJ buddy

Oh yeah check it out because that is just a heat wrapping around the O2 wires. You think about it , it does not take much to affect that circuit. Even in the rest of the harness. Even corrosion at the connector could cause a voltage drop and that is no good because we are dealing in mili volts on this circuit. just a few mili volts difference is the difference between the ECU thinking your way lean or way rich when your not. If it is extream like in my case the ECU thought I was way to advanced in my timing so it instantly retarded my ignition timing so much that it felt like I was not in control of the throttle. Good luck. Over look nothing right

Yeah so slim fans on the way from silicone intakes. I heard from others they were good and for the price I can't argue. We will see how they come out.

I may have to check mine out also im running a stock RR with just an intake and when i come to a stop or shut the car off im smelling raw fuel and its shuddering a misfiring during normal driving which for me is shifting about 3k rpm..... <---def not good lol thanks