Monaro Check Engine

[Yanayaya]

Made it home after a worrying drive. So I started my journey home, no problems to speak of stopped at traffic likes and the engine started running lumpy, you could see the gear stick wobbling a lot, then check engine came on. It then went off and the engine started running nicely again. Then a little later it came on again right after the engine started running lumpy.

I plugged in my ODBII reader and set my phone up to pull out any codes, as soon as check engine came on I ran the reader it always comes back with nothing. As far as it's concerned there are no codes. Now the fault could be classed as intermittent because it comes and goes for the entire journey. Needless to say the car won't be moving till I figure out whats going on but with no point of reference and no apparent stored code what do I do?

Any suggestions? Let's assume for the moment that I can't get it to a garage because there isn't one nearby. If needs must I can have her taken their (recovered) from my home.

[Mud_]

Are the spark plugs and leads original?

[Yanayaya]

Mud_ said:

Are the spark plugs and leads original?

Nope they are all brand new, Magnecore Leads and AC Delco plugs, all installed about 3 months ago.

[snowwolf]

Double check they are all pushed home, something intermittent is normally a dodgy connection, well hopefully it is.

[Aitch 'H']

I assume you've got headers fitted. Don't want to state the obvious but have you checked that the leads aren't starting to melt on the headers? Or possibly the O2 sensors starting to break down?

[Yanayaya]

I've just had a thought....this might be my fault this EML. DOH!!!

When I had the car decatted the shop popped the post cat o2 sensors in without spacers (restrictors) and so since that day the post cat o2 sensors have been getting too much exhaust gas passing by them which over time has led to this. It's a thought but the best place to start, I'll crawl under tonight and install them and see if it helps. Hopefully I've not damaged the sensors beyond repair.

[Yanayaya]

Aitch 'H' said:

I assume you've got headers fitted. Don't want to state the obvious but have you checked that the leads aren't starting to melt on the headers? Or possibly the O2 sensors starting to break down?

I do yes, I'll have a look. When I installed my headers I also installed heat socks on the leads to protect them just in case.

[Mud_]

You can space the rear O2 sensors, but I would just get them mapped out. Perhaps there's someone friendly near you with EFI live.

[Yanayaya]

Mud_ said:

You can space the rear O2 sensors, but I would just get them mapped out. Perhaps there's someone friendly near you with EFI live.

My local tuning garage might be able to help. I'll check in the new year, in the mean time I'll see if the spacers help.

[Yanayaya]

Tonight I went to do a little bit of investigating, checking leads, heat socks, coils etc etc and everything is perfect and exactly how I left it BUT I happen to glance down and I saw the AC belt pivoting on the edge of it's pulley. This isn't the problem I initially set out to cure it's just something else I found whilst looking around. I changed ALL the front pulleys and belts about 3 months ago just after her service. All parts came from monkfish too.

It seems to have shaved itself down an entire tooth.


Damage all around the edge


Pivoting on the edge of the pulley


This isn't the first time this has happened, in fact the reason I replaced all the belts and pulleys in the first place was because the original AC belt snapped. Now this is happening, it's been fine for 3 months. Could my rough running LS2 due to my problem have caused this level of jumping on the belt? Unreal.

[snowwolf]

Perhaps just after you fitted the belt it decided to hop over and has run like it since then, fit a new belt and see how it goes if everything else looks ok