Error Code Help

[Yanayaya]

Evening Fellas,

I'm after a bit of help before I got pulling my LS2 to bits :-P to bring you up to speed a few months ago I was talking about problems with my monaro running rough since I had the car decat. The problem is persisting and in many ways has gotten worse with the EML coming on most of the time now. No fault code reading device would pick the codes up so I took the plunge and purchased a full tune EFI Live V2 from Richard.

Before I go any further let me give you the spec for my Monaro just so you all know what's been done to the engine.

- VCM Air Intake (K&N Filter)
- MSD Coil Packs
- ProFlow Headers
- Decat pipes
- Wortec switchable exhaust
- Magnecor Leads
- New AC Delco plug (part of service 5 months ago)

and I'm about to take delivery of FAST intake and fuel rails but don't want to go much further till I resolve these issues.

SYMPTOMS

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Whilst driving the car and say sitting in traffic the engine would start to really shake (enough to make the AC belt jump off its pulley). Then the EML would go on, once you got moving she would settle down and the EML would go away. There was always a strong smell of fuel too. On the duel carriage ways etc it wasn't a problem it never came on (until this weekend). Now it's coming on more and more and everytime it's the same behaviour, engine shaking likes it dropped a cylinder.

CODES

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So originally I wasn't getting any fault codes but Richard assured me that if the EML is going on then your scan tool will get the codes (in other words you're being a donut Allan haha), so I sat and fiddled with it this evening and I now have them, 3 of them to be exact. These are as follows (descriptions of faults are what I took from google).

- ECM / P0171 / --PHX--I / Oxygen Sensor in bank 1 has detected a lean condition
- ECM / P0174 / --PHX-CI / Oxygen Sensor in bank 2 detected a lean condition
- ECM / P0689 / ---HX--I / Engine Control Module (ECM) / Powertrain Control Module (PCM) Power Relay Sensore Circuit Low

Error code P0689 might be present because the car wasn't started when I was getting the codes out (you get the same error from RPM signals on other cars if the cars not started).

There you have it, this is where I am at. I expected the condition to be rich if I'm honest but if it's lean it explains the smell of fuell as the engine tries to compensate. In my opinion as a none expecrt on these things is that I don't think it's really lean I think there is something wrong with the o2 sensors perhaps due to the decat and O2 spacers but generally all the extra fuel it chucks down is making the engine run lumpy in the way it does.

I'm currently open to any advice anyone has perhaps you've had the same problems. Should I consider changine my o2 sensors? Should I perhaps clean my MAF? Not sure where to start to be honest.

[Mud_]

Log some data!

Make sure if includes PIDs for the MAF and voltages from the o2s, as well as the usual suspects to help you understand the data (wideband if you've got it, commanded AFR, spark angle, MAP, RPM, IAT, ECT, VSS, KR, STFTs, LTFTs, etc.).

[Yanayaya]

Well I've logged data before and nothing seemed to show up when the data was looked at, I'#ll do it again and localise the data to the o2 sensors and fuel trims.
From what I understand the car has an air leak somewhere and finding it isn't proving easy. I cleared all the codes and once the car EML came on again over the weekend only two codes that were reported back:

- ECM / P0171 / --PHX--I / Oxygen Sensor in bank 1 has detected a lean condition
- ECM / P0174 / --PHX-CI / Oxygen Sensor in bank 2 has detected a lean condition

So I need to find this vacuum leak, can anyone recommend vacuum lines that are worth a check on the LS2?

- I have removed the intake pipe and checked it
- I've removed the throttle body and checked the seal which seems ok
- I've checked the filter and that's all ok.
- I've nipped up the header bolts all round.

The only thing left is the exhaust and intake I guess.....

I'm open to suggestions at this point in case there is something I might have not checked that could possibly help.

[ringram]

Also as you changed coils you might have a bad coil or plug lead, which contributes to rough idle.

Though in theory you should have a P0300 error for misfire. Worth checking anyway as a miss will show up as lean too!
But both banks is interesting.

As an aside Ive not heard good things about MSD coils.. http://ls1tech.com/forums/generation-iii-external-...

You might want to switch coils back as part of your troubleshooting and see how you go..

[Yanayaya]

ringram said:

Also as you changed coils you might have a bad coil or plug lead, which contributes to rough idle.

Though in theory you should have a P0300 error for misfire. Worth checking anyway as a miss will show up as lean too!
But both banks is interesting.

As an aside Ive not heard good things about MSD coils.. http://ls1tech.com/forums/generation-iii-external-...

You might want to switch coils back as part of your troubleshooting and see how you go..

For the sake of testing yeah I agree it's going to need to be a quick coil check too but as you said I would have expected a misfire code to pop up. I'll pop the old units back on and see what happens. IIRC the problems with MSD coils was pre 2011 where their rep was burned for their poor quality but I was told it was all sorted.

Since my last post and since speaking with Richard I did test a theory surrounding my throttle body. As I was running out of options I looked at the sealing between my intake and my throttle body, the ring looked in good health but I thought for the sake of argument I'm going to put a dam of instant gasket on this, just as a last resort. Interestingly the day after I took the car for a very long drive and for over 2 hours which included traffic sitting the EML never came on, it did eventually but it was brief. Then on the way home it did it again at around 60mph but only very brief and never came on again. Now this could be a total red herring but I thought it would be worth mentioning.

Also thanks Richard for being so helpful and for allowing me to phone, I know you're not a tech support line but your assistance on this has been invaluable.