benzokirk

Here's the scenario:

I developed a bad primary cat, and replaced both primaries with a set of Kleemann long tubes this past weekend. I drove around for a couple of months with the bad cat and, the CEL was on the whole time. For the last couple of weeks before the ling tube install my car started to misfire, and I attributed this to the cat being clogged. I'd pull over, turn the car off, then fire it bad up again and it would run fine. Again, I figured it was because of the clogged cat.

When I pulled away from my indie shop I noticed the CEL wasn't on. Fine. Drive about 5 miles and it comes on, starts flashing and starts misfiring again. Pulled the codes and got:

P0300 - Multiple Cylinder Misfire
P0100 - Mass or Volume Air Flow Circuit
P0130 - O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
P0305 - Misfire Detected in Cylinder 5
P0304 - Cylinder #3 Misfire Detected, catalyst Damaging
P0307 - Misfire Cylinder #7

I should've also pointed out that my indie shop's computer is down at the moment, so I have to wait for my ECU flash.

Question: Could the lack of corresponding ECU flash after header installation cause any of the codes thrown above?

Too bad I didn't pull the codes before the header installation, to compare...

Solo wing

Maybe something else is causing the codes?
As far as I've seen, deleting cats will not cause misfiring and drivability issues only a CEL and emission failure.
(remember seeing a W211 E55 with deleted cats/ no tune but with a CEL it ran fine)
I would start diagnosis step-by-step:
1- Disconnect the MAF, if it runs worse the MAF is fine. If it runs better clean or replace the MAF.
2- Swap the location of the coil packs and see if the problem moves with it or not.
3- I'd also recommend a hard rest, either by STAR or disconnecting the battery overnight (It does wonders this one)
I can't remember anything else for now, hope someone will chime in.

benzokirk

Good advice, Solo wing, thanks! I'll do the battery disconnect tonight since I won't get around to the MAF until after the holidays, if I don't tackle it tomorrow.

I also thought about the coil swap out... but do you think anyone these issues would clear up immediately upon turning the car off and then on again?

That's the part that stumps me.. You'd think if it was an issue it would still be there when you restart it, no??

Solo wing

I believe the code regarding the cylinder misfire will move or clear up immediately. If the problem was indeed the coil packs.
(stupid question) but did you try clearing the codes, I use a cheap $5 Bluetooth OBD reader + My smartphone.
Are the codes pending or confirmed?
I remember pending codes were easily and immediately cleared.
For confirmed codes I had to drive for a few minutes until the code cleared it self.

Good luck.

benzokirk

Not a bad question, but the codes won't clear. At this point I can't drive very far without the same symptoms resurfacing. I drive it. It misfires. I pull over and turn the car off. I restart it. It runs fine for awhile until it misfires again.

The CEL never goes away.

I am about to go to the garage and disconnect the battery now... reconnect in the morning and see what happens. if it resurfaces tomorrow I'll try disconnecting the MAF. I'm sure I'll order one and replace it, just in case...

benzokirk

Thanks!

Installed a new MAF, all codes went away and car ran much better for about a day. The next day CEL came back, car started running rough again, and even though the MAF code went away, these codes popped up:

P0130 - O2 Sensor Circuit Bank 1 Sensor 1
P0135 - O2 Sensor Heater Circuit Bank 1 Sensor 1
P0156 - O2 Sensor Circuit Bank 2 Sensor 2
P0161 - O2 Sensor Heater Circuit Bank 2 Sensor 2

I guess I need a new set of sensors now. These are all pending codes, except P0130, by the way...

snooozie

Hi,

Wondering if you got these resolved. Looks like you have a bad set of O2 sensors.