Hello all. Had my beast for over a year now but probably this is the first post I am making (recently got permission to post) so I shall dig right in.
I shall first go over the mods that were already on the car when I bought it: 1) supersprint headers (catless), hartge accelerator booster, K&N typhoons.
Mods that I did : secondary cat delete.
So now my beast was catless and the smell of fuel in the cabin nearly killed me (this is later solved, read on.)
Now once I had gotten it it threw a bunch of codes mainly misfiring with cylinder cut-off on almost all the cylinders but these were cleared,
2B35: Misfire with cutoff cycl 1
2B36: Misfire with cutoff cycl 2
2B37: Misfire with cutoff cycl 3
2B38: Misfire with cutoff cycl 4
2B39: Misfire with cutoff cycl 5
2B41 : Misfire with multiple cylin..... etc etc you get the idea
Got a new clutch for the monster and did the SMG adaptation procedures and what not (Transmission no ISSUES.. knock on WOOD). The car ran fine for 2-3 months and then BAM!! MISFIRES on a whole another level.... my Vanos inlet and outlet gears were out of order. So like any good m5 owner I gave it the utmost attention got it changed pronto, and the car was as good as new no codes (well the oxygen codes kept popping up, but I figured I have no cats so maybe that is the case)
Took the car out and while testing in M-mode in 3rd and 4th gears specifically it threw the CEL (**REDUCED ENGINE POWER....
). Guessed maybe the coil packs are bad changed them along with a new ionic sensor (on one bank) it seemed fine, but BEHOLD the fumes you had read about previously still there. The garage I am learning to work on cars (YES I am new to the automobile scene but we all start somewhere) nearly chocked on the vapors and had to take precautions to not suffocate. Now at this point I thought to myself that being catless this was a normal occurrence to but now come in the O2 sensor codes... so I swapped the 02 sensors and LO! my idle had dropped and the gas smell was next to normal!
Now the engineer who I am currently learning all these great things from the vehicular dreams world took the car again for a test and it starts misfiring again as to no apparent reason, so now we are stuck again back to square one. I have scorched the forums for all possible leads and like any great detective we all start from the crime scene the codes will be read tomorrow to see what we got now.
And then come my questions :0
1) Being catless would definitely require a tune? The closed loop control in the M5 or any other car for the matter reads the lambda values from the pre-cat sensors (which I have in place) and adjusts AFR accordingly and the post-cat O2 sensors are more for the outer-loop-control to fine tune the AFR. Having no cats at all without a tune could be attributing to these faults? Maybe?? Possibly??? Definitely????
*** the funny thing is that once the new O2 sensors were placed the idle jus dropped and the intoxicating fumes were gone! :s
2) The spark plugs were blacked out but they were recently changed. We figured since the car ran rich all this time maybe they just fouled it could they be the culprit? (checked the sparks too they are find but a recommended change)
3) I had a doubt on these stupid k&n s but the MAF readings were normal ......
4) Maybe it is a glitch in the M5 MATRIX? (DME-issues)?
5) Checked the valves/valve springs all in order...
6) Fuel injectors cleaned
7) Bad fuel (
m I knew I shouldnt have put gas in from the stupid gas station , but I live in Qatar so gas is almost uniform all over but you never know)
NOW what you ask well I want to know from all the ESTEEMED members of this brotherhood to help another brother out. Though I have not dirven my car properly for the past 4 months the learning experience I have is worth it (Wish I can say the same for the money I spent lool). The thing is I believe in the experience rather than the finances ( I know need to grow up, but I aint married my only wife is my baby M5).
So if you all could help me narrow down the ifs and buts I would greatly appreciate it and now that I can post well I will keep you updated on a DAILY