Continual Misfire CEL woes

ImprezaRSX · **Joined:** Tue Jul 25, 2006 8:47 pm **Posts:** 145

Hey guys,
I'm still getting misfire CELs.

If I disable the CEL, the light comes in and I can't read it.
If I enable the CEL, it pops up whenever it feels like it. Some or all cylinders, it doesn't matter, and usually it's not even perceptibly misfiring. Sometimes it misfires like a big dog because this Perrin Blow Thru tube is a POS s*** design that fills the MAF with water/oil/dirt and has a transition before the sensor that causes the MAF voltage to fluctuate constantly.

car is an 07STi.

I know there was a lot of talk about fixing the misfire CELS and even adding a misfire counter to the maps, but I don't see that on this ROM. Is that a 16bit thing only?

Just wanted to add that I disabled the P0000 codes as well and it still does it.

Thanks a ton,
Dominic

merchgod · **Joined:** Thu Mar 30, 2006 2:38 am **Posts:** 5336

What are you using to read the codes?

ImprezaRSX · **Joined:** Tue Jul 25, 2006 8:47 pm **Posts:** 145

I've tried everything from MAC scanners to ecuexplorer.

ImprezaRSX · **Joined:** Tue Jul 25, 2006 8:47 pm **Posts:** 145

oh, and another question:

Is there a MAF voltage Filter? Something I could bump up a little to help with the fluctuating voltages?

merchgod · **Joined:** Thu Mar 30, 2006 2:38 am **Posts:** 5336

I've never heard of anyone having problems disabling misfire CELs with the 32-bit ECU as long as they also disable both P0000 codes. I wouldn't even bother with Ecuexplorer in reading codes. I would make sure that when you did try using a true obdii scanner (if you did) then you disabled both the misfire codes AND the P0000 codes.

There's no way to "filter" MAF voltage, that I'm aware of anyway, at the ECU level.

ImprezaRSX · **Joined:** Tue Jul 25, 2006 8:47 pm **Posts:** 145

all of the above was done....

I've seen a lot of things that I doubt everyone has seen.

For example, I was working on a car and the CEL came in. It was telling me there was a fault with the rear 02 sensor. Which was really weird because that CEL was disabled. Then I noticed the TGV was unplugged. I plugged it back in and the CEL cleared. Yet my MAC OBDII reader said rear O2. So did ecuedit and ecuexplorer.

If I can gather any more data, I will.

merchgod · **Joined:** Thu Mar 30, 2006 2:38 am **Posts:** 5336

ImprezaRSX wrote:

For example, I was working on a car and the CEL came in. It was telling me there was a fault with the rear 02 sensor. Which was really weird because that CEL was disabled. Then I noticed the TGV was unplugged. I plugged it back in and the CEL cleared. Yet my MAC OBDII reader said rear O2. So did ecuedit and ecuexplorer.

I can guess what happened there. Your MAC scanner does not have Subaru specific code definitions. With CEL codes in that range, the actual description can be vastly different between manufacturers and sometimes you just get a generic description that isn't anything close to the Subaru specific description. These are all TGV codes below, but you can see "O2" in some of the descriptions which is where you thought it was the O2 sensor, when in fact, it was the TGVs, just that your scanner didn't support Subaru descriptions:

Code:

P1086 Fuel Control Mixture Rich (Bank 2 Sensor 1)

P1087 O2 Sensor Circuit Slow Response in Lean Control Range (Bank 1 Sensor 1)

P1088 O2 Sensor Circuit Slow Response in Rich Control Range (Bank 1 Sensor 1)

P1089 O2 Sensor Circuit Slow Response in Lean Control Range (Bank 1 Sensor 2)

P1090 Pre-Catalyst Fuel Trim Too Lean Bank 1

P1091 Pre-Catalyst Fuel Trim Too Rich Bank 1

P1092 Pre-Catalyst Fuel Trim Too Lean Bank 2

P1093 Pre-Catalyst Fuel Trim Too Rich Bank 2

P1094 O2 Sensor Circuit Slow Response in Rich Control Range (Bank 2 Sensor 1)

P1095 O2 Sensor Circuit Slow Switching From Lean to Rich (Bank 1 Sensor 1)

P1096 O2 Sensor Circuit Slow Switching From Lean to Rich (Bank 2 Sensor 1)

P1097 O2 Sensor Circuit Slow Response after Coast Down Fuel Cutoff (Bank 1 Sensor 1)

ImprezaRSX · **Joined:** Tue Jul 25, 2006 8:47 pm **Posts:** 145

you're so smart.

I love having you on my side.

merchgod · **Joined:** Thu Mar 30, 2006 2:38 am **Posts:** 5336

no problem.

It might not hurt to try another obdii scanner if you can borrow one as it pertains to your original issue. And make absolutely sure that the both P0000 codes and all misfire codes are disabled in the flashed ROM.

ImprezaRSX · **Joined:** Tue Jul 25, 2006 8:47 pm **Posts:** 145

yeah, I just triple checked my ROM to ensure that the codes were out.

I even opened a new factory rom and started from scratch. Disabled all the codes again using the newest Rom Raider Defs as well as transferred all my experimental mapping.

Oh another really good question:

Could you write something in the code that would enable the Air Pump to run continuously when the engine is running?
All I need is the air pump to run constantly (regardless of the solenoid). That's it. Nothing fancy. Is that even possible?

merchgod · **Joined:** Thu Mar 30, 2006 2:38 am **Posts:** 5336

ImprezaRSX wrote:

Could you write something in the code that would enable the Air Pump to run continuously when the engine is running?
All I need is the air pump to run constantly (regardless of the solenoid). That's it. Nothing fancy. Is that even possible?

I don't know - I haven't messed with the air pump stuff. Why would you want to do that?

ImprezaRSX · **Joined:** Tue Jul 25, 2006 8:47 pm **Posts:** 145

I have converted my air pump into a vacuum pump for my PCV since a blow thru doesn't allow you to use the intake pcv valve (vacuum leak). It works great if I short out the relay to get it to run. However, if we could program something in the ecu, it would make the conversion easier for anyone who wanted to do this.

Plus, vacuum pumps make power by sealing the rings better and not plumbing post combustion gases into the engine thereby displacing oxygen. I have to do it because my rotated setup is blowing oil out the turbo seals due to lack of vacuum in the crankcase. I bought the kit used and thought the turbo was bad. Bought a new turbo and nothing changed. Fixing the PCV by adding vacuum, fixed the issue.

Once I finish the testing of the pump, I'm going to post a thread on doing the mod so anyone can take advantage of this.

williaty · **Joined:** Tue Jul 24, 2007 10:28 pm **Posts:** 349

merchgod wrote:

disabled both the misfire codes AND the P0000 codes

Why, and when, is disabling the P0000 codes required?

absubtle · **Posted:** Thu Feb 19, 2009 6:13 am

ImprezaRSX wrote:

I have converted my air pump into a vacuum pump for my PCV since a blow thru doesn't allow you to use the intake pcv valve (vacuum leak). It works great if I short out the relay to get it to run. However, if we could program something in the ecu, it would make the conversion easier for anyone who wanted to do this.

Plus, vacuum pumps make power by sealing the rings better and not plumbing post combustion gases into the engine thereby displacing oxygen. I have to do it because my rotated setup is blowing oil out the turbo seals due to lack of vacuum in the crankcase. I bought the kit used and thought the turbo was bad. Bought a new turbo and nothing changed. Fixing the PCV by adding vacuum, fixed the issue.

Once I finish the testing of the pump, I'm going to post a thread on doing the mod so anyone can take advantage of this.

Not to high-jack this thread, just a side-note on the air pumps. They are not meant to run continously. I have removed quite-of-few of them. I use them for various needs. My friend borrowed one to inflate and deflate an air mattress for camping. It worked well for awhile, but the 2nd trip it got so hot it partially melted and stopped working.
I put one on my supercharded Tacoma truck in the exhaust stream right before my cat, to help pass 4-gas emissions here in Colorado. But that pump survived, even w/ exhaust blowing out of the vent.
All I am saying it might be better to have other values to help keep it from frying. Perhaps even duty cycle controlled.
Ok, anyway, carry-on.
Absubtle
CO

merchgod · **Joined:** Thu Mar 30, 2006 2:38 am **Posts:** 5336

williaty wrote:

merchgod wrote:

disabled both the misfire codes AND the P0000 codes

Why, and when, is disabling the P0000 codes required?

Only when disabling the misfire codes.

RomRaider

Continual Misfire CEL woes

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