HELP ! check engine light >.<

[br3nny]

hey

i got a problem with my check engine light coming on on my fn2r ... i was wondering if anyone had any insight into what could be wrong ?

the only mods so far...
custom cat back exhaust (single 2.5'' pipe all the way with a center muffler) and injen cai

what has happened so far is every time i disconnect the battery the car is fine (no engine check light). After a while just driving around normally check engine light will come on.

doing the diagnostic check there are no DTC errors

the only common factor i can deduct is the damn hot ass weather !~!!! outside 32-37 deg C

[ekdez]

might be your injen?

[liquid23]

which was installed last? CAI or cat back?

if CAI then the sensor?
hmm does FN2R run MAP or MAF sensor? if MAP sensor then shouldn't be a problem.

if MAF sensor i thought injen was just plug and play?
i know all about MAF sensor lol... the money that went through to fix my intake -_-"

[ekdez]

so the gruppe-m wasnt worth it?

[curtis265]

unplug the ECU fuse for 5 mins and put it bak in. Then if it comes back lookat more possible solutions

[br3nny]

which was installed last? CAI or cat back?

if CAI then the sensor?
hmm does FN2R run MAP or MAF sensor? if MAP sensor then shouldn't be a problem.

if MAF sensor i thought injen was just plug and play?
i know all about MAF sensor lol... the money that went through to fix my intake -_-"

the CAI and the exhaust were both done at the same time

i'm not too with which sensor it is but i did find someone else say that the "MAF as primary load sensor"
what did you have to go through to get the intake fixed...sounds like alot of labour time costs coming up !!!!

[JOhnnyFD]

the INJEN for the FN2R should fit fine, INJEN CAI are dynoed tuned and fitted specifically for the model.. there could be a problem with the install then

who install it for u?
if u DIY, get a mechanic to look it over
if a mechanic did it, get that mechanic to look it over and if problems still persist.. get another 3rd party mechanic to check it

for the gruppe-M the guys are talkin abt is fitted for FD2R and not FD2 so mods needed to be done for fitted

[aaronng]

FN2R has an AFM (black box that is on the stock plastic arm closest to the airbox side). If your CAI's diameter is different to the plastic arm or if there is different turbulence in the CAI, then that can cause the CEL.

[liquid23]

so the gruppe-m wasnt worth it?

well it is worth it after you get it to work haha. All you need to do it just cut off the OEM MAF sensor part and use it in the new piping that needs to get made up (total cost would be bout $300). The guy in s'pore that i got the info off for the FD2 to fix mine, the MAF adapter cost him SGD$30! y australia so expensive.


the CAI and the exhaust were both done at the same time

i'm not too with which sensor it is but i did find someone else say that the "MAF as primary load sensor"
what did you have to go through to get the intake fixed...sounds like alot of labour time costs coming up !!!!

FN2R uses a MAF sensor as i can gather from this pic by lukits01
http://img210.imageshack.us/img210/4002/dscn1280ed1.jpg
the diameter where the MAF sensor sit has to be exactly the same as OEM. I am sure Injen figured this out before they made the parts. Need to make sure anyway that where the sensor sits is the same diameter as the OEM.

i'm not sure about the cat back part of things but is there an O2 sensor that goes in the piping somewhere? or is the O2 sensor the MAF sensor? :confused: but i think the main problem will be with the MAF sensor.
Also if unplugging the battery to reset the ECU and the light keeps coming on just leave the light on because your car will be running the same either way until the problem gets fixed. Maybe ask your mechanic to plug the ECU into computer to see what code it throws up, so you can sort the problem out.

[aaronng]

doing the diagnostic check there are no DTC errors


If the CEL is on, then there will be an error code stored in there. How are you trying to read the codes? Are you using an OBDII reader that is compatible with Hondas?

[br3nny]

thanks for all the replies......theres a self check thing that you can do that i read on civinfo....brings up all the DTC errors on the screen in the dashboard (basically short the fuse slot that they usually stick the plug into)

but the weridest thign happen

i was on my way back from a bbq .... 40C day today ... and half way i noticed that the engine light isn't there anymore

could this be the ecu learning to deal with the hot weather conditions ??? i must admit the other times that i left the engine light on it didnt' have as much run time as this time around...

[br3nny]

...........it came on again -_-

[aaronng]

thanks for all the replies......theres a self check thing that you can do that i read on civinfo....brings up all the DTC errors on the screen in the dashboard (basically short the fuse slot that they usually stick the plug into)

Use an OBDII tool to read the code. It might be throwing a Honda-specific Pxxxx code which might not come up with the fuse method.

[br3nny]

Yep .. got to organise a time to get it checked out...

will keep you posted

been keeping a log of the ambient temperature etc and times the damn thing keeps coming on and off....so far so good and its kept itself off

[lithium]

Use an OBDII tool to read the code. It might be throwing a Honda-specific Pxxxx code which might not come up with the fuse method.

yes, yes, yes, yes and yes! :) when a check engine light comes on, use a code reader and get that error code out of the ECU - it will tell you exactly where to start looking.

if you don't want to pay a mechanic to do it and you have a laptop you can buy USB code readers for $100 (google for 'elm327') - probably how much it costs for a normal auto-electrician to diagnose the problem anyway

i can make a good guess at what it is mate. normally on modern engines there are two O2 sensors, pre cat and post cat. if you have a catback system the post-cat O2 sensor will have to be moved, which often means the O2 sensor wiring is extended/shortened. ask the guy who did it how he wired it up, or go under the car and take a look yourself. if they didn't do a good job extending the wires you can get intermittent connection problems to your O2 sensor causing the ECU to think it's shat itself and put up a check engine light.

good luck, your first port of call with OBDII systems is ALWAYS a code reader! :)

[br3nny]

thanks to lukits i managed to get the scanner while the engine light was on

error code read P0172 which means the car is running rich ....

now to see if it was the intake that was causing the problems !!!!

[maracer]

hmmmm....cel just came on my car aswel?
Car is running fine.....and has no mods done to it!
Think i'll see the Honda dealer on Monday, Still under warranty.

[aaronng]

thanks to lukits i managed to get the scanner while the engine light was on

error code read P0172 which means the car is running rich ....

now to see if it was the intake that was causing the problems !!!!

Check if your MAP sensor is still working fine.

[p3p5y]

I'm not an expert in this field, but I did quite a bit of diagnosis when my check engine light came on. It turned out I had to replace my primary O2 sensor. In your case it may be different.

During my research, I came across a method to bypass the secondary o2 sensor using a defouler. There's some background information as to what would cause the light to come on and the technique to overcome this. If all other things don't work, try giving this a go:

http://www.8thcivic.com/forums/exhaust-discussion/82998-mother-all-defouler-threads.html

[aaronng]

It could also be the primary O2 sensor like p3p5y mentioned. However I doubt a defouler would fix the problem since a different code is involved if you trigger the secondary O2 sensor (P0420, cat efficiency below threshold).

[white_ep3_civic]

I had an engine light on my car for 2 reasons.
1. the O2 sensor in the cat needed replacing
2. the sensor in the cai was in properly
Not the best advise but hope it can help a little bit