Help me pass emissions..

[r4esh]

Resurrecting this thread for any potential users facing similar issues. Here is the update.

I took the car to a local shop that has done a few of these swaps. He read my diagnostics port and immediately decided my O2 sensor had failed. I had created an "extension" in my o2 sensor wiring to reach my engine harness side adapter and he thinks thats where the issue came from. Originally I didn't leave myself enough length and it was either pull the intake and give myself more wire to work with... or cut the o2 sensor wiring and add it. I went with the later. That was over a year ago though.

SO I decided to pull the intake and correct the o2 wiring issue. I cleaned up everything nicely again, including the idle control valve. At the same time I replaced all 6 injectors with rebuilt injectors. After putting it all back together the car is running great and doesn't "smell" rich anymore.

Tuesday morning the car is going to attempt emissions again... fingers crossed.

[VinniE30]

My s50 has failed the last two test cycles ever since I installed the Bimmerworld Shrick cams kit (injectors, tune etc). With stock setup I would "Fastpass" easily.

Last time around I tried the CRC Guaranteed To Pass product but there was virtually no change in the results.

I also installed a Magnaflow cat and it made no difference over the generic cat that had been in use.

Good luck - I feel your pain!

You're in maryland just register it a historic.

[r4esh]

OKAY back again... Almost a month later and I still can't pass emissions. I wired up a check engine light, tested and works awesome. I have NO check engine codes or anything I can stomp test... so that didn't help me trace the issue. No check engine lights... passing under load, but still double the hydrocarbons at idle.... SOO frustrating... maybe the cats I'm using are too small?

Anyone have any ideas, I'm completely stumped here. A friend is suggesting I unplug one of my injectors and run through emissions that way on 5 cylinders. He says its a nifty trick that worked for him every time. Anyone?

[oldmann]

Had similar issues in Colo. with M42. Failed 5 times on the roller setup they use here.
1st fail was for leaking coolant, New radiator, all hoses, including all vac. lines
Got close to passing after relacing the TPS.
Then jumped in the middle of the fuel system. Fuel pump was low on pressure, replaced fuel filter, replaced pump, failed.
FPR was inconsistent with pressure all over the place. Replaced it, failed, just not as bad.
Coolant temp sensor was reading slow changes in temp, wouldn't code, but not correct, replaced it, Passed.
7 tests 5 months, too many $"s to talk about. Combination of many things.

[328ijunkie]

how is your CCV drain routed? back to your dipstick?
You mentioned the temp sensor is new. Did you replace the ECU temp or cluster temp sender? Is it plugged into the right place? Can easily be plugged into vanos plug incorrectly.


High HC is basically too much fuel for one reason or another; Causes:
Tuning
Injectors oversize for tune
Injectors sticking
Vac leaks
Engine still in cold start loop (ECU coolant temp sensor correctly plugged in/functional?)
coils=misfiring=unburned combustion charge entering exhaust
plugs==misfiring=unburned combustion charge entering exhaust
Cat undersized/broken
more im forgetting...

[325Projectz]

fyi, my car failed with magnaflow cats like mentioned here. i installed an obd2 cat setup, passed the first time after that. obd1 s52.

[r4esh]

I REALLY dont want to source / weld in OBD2 cats... I hope it doesn't come to that. I have no check engine lights. I'm using silicone intake hoses (m50manifold.com kit), no air leaks, new NGK iridium plugs, high flow cats are less than a year old, rebuilt injectors, tuning from TRM is supposedly proper (unless they sent me the wrong chip). The car runs smooth, but I can feel a little bit of "the engine" through the shifter, not sure that would constitute as feeling misfire or timing being off. The car runs and drives awesome.

I've got a RedLabel DME with m50 chip coming in the mail. I'm going to run through emissions with 1 injector unplugged tomorrow morning, if that fails then I'm going to go run through with the m50 tuning.

[Jalves619]

how is your CCV drain routed? back to your dipstick?

Also interested in this. You didn't weld a drain onto your e34 dipstick if i remember correctly. Are you sure you aren't getting oil vapor through the PCV cyclone?

[r4esh]

Actually I'm using the welded dipstock that I bought from 328ijunkie :) SO PCV is running normal OBD2 style, from the vent into the filter and back down to the oil pan dipstick. I'm also running the m50manifold.com kit so that makes it hard to screw up how its vacuum is pulled.. Could my PCV be screwed up?

[r4esh]

Both temp sensors are new... IS there some kind of scan tool tell me what temp they are both reading? For that matter all other sensor values?

[e30user]

Both temp sensors are new... IS there some kind of scan tool tell me what temp they are both reading? For that matter all other sensor values?

I'd like to know this as well. In regards to the engine coolant temp sensor, I seen some people measure resistance with a multimeter, but I don't know what the expected values are supposed to be. Just as another shot in the dark, could a bad air intake temperature sensor also cause a rich mix? I'm not sure if you already looked into that.


I may have missed it, but have you tried getting tested with the stock ecu/maf/injector setup that was mentioned in a previous post? I doubt that's the true source of the issue since I've read stories of e36 guys passing with that setup without issue. It could still be worth a shot if you're completely out of ideas. Also, how long has it been since your last oil change?

[328ijunkie]

DIS or a Snap on something or other is about the only scan tool that will read out live scan data.


Just measured a random OBD1 ECU CTS i had laying around
3.010KOhms and its about ~60deg here in the shop right now.

If you have the ECU sensor (blue base) plugged into the stock E36 cluster sender (black base) then that can cause issues (though i dont remember which way) as the resistance values for the sensors are different.

[r4esh]

Well.. this thread shall live a little longer so we can figure this out.. but in the meantime... GOOD NEWS!

I passed emissions! hahaha.... I ran through with one injector unplugged so I was just firing on 5 and I just BARELY passed (220 hc max allowed and my car got 220). lol I just put a tiny piece of electrical tape over the injector plug and tightened everything up so that the inspector couldn't see my "fix".

I don't want to leave it at that, because its not a final solution to the issue. That and for the sake of anyone else having similar issue to me, mark my words I'll figure this out!

[Pipes]

Sooooo... did you figure it out? I have EXACTLY the same setup (OBD1 S52, Euro MAF, headers) and the same issue. No vacuum leaks, new plugs, oil change, new fuel pump/filter, new Magnaflow cat. Drove HARD for 20 minutes prior to test- cat was HOT. Even put a quart of alcohol in the tank. Passed everything beautifully except idle emissions. 220 allowed, 420 reading. It was my 5th try and my tabs expire tomorrow.

[Pipes]

Passed!

In case this helps anyone else, I ended up adding a second cat. The Magnaflow one was apparently worthless because when I put in the Walker 80301 and retested, it passed absolutely flawlessly. Only drawback is the Walker is 2" in and out, so the shop had to open it to 2.5" in and out to install it (no big deal- install was $88.)
Before and after: