Its been mentioned many times before, but Im going to say it again...the quality of this kit is superb and very complete. Reggie was extremely helpful on getting my ECU back on time. Thanks Reggie!

Installation went smooth with no problem except trying to fit the downpipe with the Nismo headers...but we got it to work.

The car starts right up the first time after the install. No problem. Idled for 10 mins, drove it around the block, went back for a final check up, and went on my way. The car pulls like a mother.... Very smooth.

Drove it for a day with no problem, but then the CEL came on the second day. Went back to clear the code...Engine Misfire. That was last night.

Today, it came back again. The CEL. What can be wrong?
The car runs fine. Just the CEL is on...again.

My other engine mods are...
one step cold plug.
AAM plenum spacer.
Thermo intake gaskets.
UR crank pulley.
Nismo headers.
Nismo clutch and flywheel.
Amuse Ti exhaust.

Im at 15.x a/f at idle and 10.x at WOT.
Max boost at 8.7.
I only 6600rpm it...never hit the rev limiter.

 

an occasional P0300 code is not uncommon with FI. It seems your situation is more than just occassional. Having 2 in 2 days may just be coincidental, but also may indicate an issue. Looking at your parts list, lightened flywheels, crank pulleys, turbos, and colder plugs can all lead to a misfire code. I would start troubleshooting by checking the gap on the plugs.

 

The P0300 code has been a VERY common issue with EVERY boosted car. Some cars do it more then some. 04s seem to have it the worst. As for the code its not anything to worry about. 0300 indicated the ECU sensed a variance in crank speed but did not detect on actual misfire on any cylinder. 0300 is the base misfire codes. Some 05 owners get it while still N/A!!!!!! Now if the code says 0301, 0302, 0303, 0304, etc then worry. 0300 means random misfire (not really) 0301 means misfire cylinder 1 (something to worry about). Turbonetics and a couple others have been working on figuring out what causes it to come up. Specifically more so in 04 and up Zs. I've know talked to two 05 owners who had it while still N/A with only mild mods...

 

Shoot ever since the install, SES comes on like every other day... So I just keep taking the negative off to reset it... Well until it comes back again

But def. getting to the point I am just going to let it stay on lol.

 

This sucks. I had this issue recently NA when a spark plug fouled @ the track essentially making me run on 5 cylinders. When I install my kit I dont want to be having to check to make sure its "just" this code and nothing else. BTW how many Turbonetics owners with an 03' Z have this issue?

 

So does 0302 means misfire cylinder 2, 0303 cylinder 3 and so on?

And yeah, I have an 04'.

 

Yea, i wouldnt be worried, you are running lightene flywheel, crank pulley, colder plugs, and boosted. Any one of these things could make the ECU sense a variance in crank speed, you are running all 4 lol.

 

huh, thats wierd i have never gotten the misfire code and i have been driving my car hard. hopefully i wont get it cause the ses light is really annoying

 

you learn to ignore it, what sucks though is you have no way of telling if something really IS wrong with the car.

I'm NA and the things I think that are contributing to it for me are my tilton clutch, UR crank pulley, JWT cams, TS ECU flash, currently lean A/F (soon to be fixed) or something else I'm not aware of. I swear my car is easier to drive when I reset the ECU and that light isn't on. As soon as the light comes on, it feels like it's a little harder to get going from a stop with the idle or something weird like that. oh well

 

Actually I think 03s get it the least. I know taurran says its not a regular occurance for him. its something that comes with the territory of putting a turbo on an N/A car unfortunately. Little annoyances like this are going to come up. Phat yes 0302 would be mis on 2 0303 miss on 3 etc. Like I said unless you have the cylinder number its nothing to worry about. Turbonetics isn't the only company that gets this as evidenced from the above posts. EVERY F/I is subject to get one and even N/A cars are getting them!!! If you are truly concerned and want to make sure its nothing there are OBDII code readers for $100 or less and even some that are laptop based to check the code and ensure its ok. I've had one thats PDA based for years now. Since the advent of OBDII its almost a necessity if you modify a car this far beyond the ECUs design parameters. I'm to the point now where I just leave it on. If there is an actual misfire event the code will continue blinking during the misfire event. And like I said some cars have it worse then others. it seems like 03-early 04 dont get it much. 04.5-05 get it the worst. This would coincide with what Tadashi says is a major processing power difference in those ECU revisions. Stupid N/A cars..

 

lol...My cel turned on about 1 month after I bought my car (installed test pipes) and it has never been off since. Actually it went off for about a week after I installed the non foulers, but then I went turbo and back on AGAIN! I am going on almost 17 months with a cel light on. YOu get used to it.

 

I see.

I have a/f wideband, boost, exhaust temp, and soon will have oil and water temp gauges installed. I guess I will just learn to ignore the CEL...I have the TCS OFF light on all the time anyways...if anything is wrong with the car, I should be able to tell from the gauges...

Any recommendation for an OBDII reader?

MIA, which one are you using?

 

I use this one: http://www.auterraweb.com/ But it has gone up i price quite a bit since I got mine and there are others out there that are just as good I'm sure. I've heard good things bout the Digimoto. It is cheaper but I couldn't compare as I have only used my Auterra one...It does work well though and if you have a PDA you can build amount somehwere in your car and just plug in the PDA when you get in and fire up the software...

 

I have an 03 and get the SEs occassionally also. But it goes away within 24 hours itself, without clearing it using OBDII. Its a little annoying but nothing too terrible.

 

i hope i dont throw a CEL light. i already have a lil collection of lights. VDC off light, TPS light, so i guess CEL will be next

 

Yeah, unfortunaely, thing like larger injectors, return fuel systems, and large amounts of boost can trigger the random code. Our crank angle sensor is amazing sensative, and samples at over 1000 times per second. If the sensor/ECU detects an abonormal acceleration or deceleration of the crank, it will throw the code. The ECU assumes that one cyclinder had some kind of misfire or improper combustion event, and triggers the code. As Mia mentioned, it's generally harmless, and is not indicative of a problem. Even idling the car can trigger the code, if your idle blips due to larger injectors, for instance. Some cars throw the code...like mine...and others do not...like Gman's, and our engines and mods are nearly identical. Interestingly enough, when I switched to a true dual exhuast system 3inch, the code went away....as backpressure can also cause misfires.

 

I got the random misfire code P0300 once when the FPR on my return fuel system broke.. I guess some fuel got into the vacuum line at the FPR and caused it.

I've also been getting P0442 "Evaporative" every 2 days recently(and it's not a loose gas cap).. but that's something emissions related so I'm not too concerned.. I can clear it with my CarPC..

--mike

 

The Evap code is likely a small leak in the return fuel fitting. Not sure if you used a special dowdy washer, with the rubber insert. That prevents leaks. If you dont have one, you can use an automotive injector o-ring, and a flat washer on both sides of the fuel pump assembly. Hope that helps!
And tiny vapor leak in the fuel system, will trigger the CEL.