Car has 68K on it and I've had too many little problems. AC drain clogged last week and in the hour it took to get it cleared, engine started dropping a cylinder (#2). Mechanic looked over plugs, coils, injectors, intake gaskets to find problem and all were negative. Theory is that ECU got wet and will need to be replaced by dealership this week. Code from service engine light says "multiple misfire". Can anyone confirm this problem? Sound familiar? Why would this happen? Then they want $500 to clear out AC system. How do I stop this from reoccurring?

 

If they replace it, its gonna be an arm and a leg. Go on car-parts.com and buy one from a junkyard to fit your car for $100-$150...

How is the car running ?? If its running good then dont worry about it and change the computer...with 70K miles on the car, the ECU should be fine..also try and find a possible leak so it doesnt happen again

-matt

 

Car runs ratty because one cylinder is not firing, so I really need to fix it because car is barely drive-able. My theory is that AC drain clog caused ECU to get wet, but I do not know for sure. Dealer will have to weigh in on it. Have checked everything else and am out of possibilities.
Thanks for the help.

 

No sh*t, I bought my 97 max with 50k and i know it sat for a little while. Anyway the lady i bought it from had just spent a ton of money trying to fix the problem your having. Actually i am going to grab the reciepts she gave me right now.............Alright got em heres what happened the car had 48k on it the cel light came on brought it to nissan and heres what the reciept says:Customer had vehicle diag at independent garage and there is raw fuel going into cyl1+2 troubleshoot per manual- ignition coil failure found replaced all coil packs and plugs cleared codes(alsoinduction service like clean injectors and that crap) at a cost of $1150....yikes!! so then a couple hours after this she said light came back on so she brought it back a week later and heres what this reciept says: customer states svc light is on..check and report...cyl 3 misfire.....due to water contamination coming from evap core falling onto ecm so then she had ecm replaced and evap hoses replaced and there is also a $180 part called valve control part#14930-3m201 i dunno exactly what that is. the total for this job was 1298.43...holy f*ck!! After this the problem was fixed, hope this helps you out. So basically the lady who had my car wasted 1200 bucks replacing all those coils which were good bc the ecu was screwed up and they didnt know it at first. I guess its good for me since i have all these new parts on my car though

 

 

I had that happen to me a while back in another SE. I started noticing that when I put my finger on the front passenger-side floor, I get this oily substance all over my hand. After a week, the carpet started discoloring. I pulled out the carpet and found out that it was coolant leaking inside my car. Turns out there was a leak somewhere above the ECU, where coolant enters into the car for the heater (I guess). Anyhow, the ECU started failing and I was getting all kinds of codes and the car felt like it wasn't running on all cylinders. Luckily I found a good independent electrical shop that was able to fix the ECU and I ended up only spending $400 versus over $900 + labor for a new ECU at the dealer. The mechanic said that the leak had gotten into the ECU! In my opinion, this is a bad design on Nissans part to have fluid running thru some ducting nearby the ECU. I wish this doesn't happen to the SE I drive now.

 

yeah. a design flaw...

I'm having this same problem right now with the ECU. The ECU was wiped off (on the outside) and reset. For the moment, I was instructed not to use the A/C and see how things go.

Knock sensor changed. O2 will be checked. I didnt realize we had 3 O2 sensors. man this is gonna get expensive.