Hawkeye D

Hi all,

2007 STi.
My a/c belt tensioner pulley packed up a few weeks ago. Got the kit from ICP and replaced the tensioner pulley and belt. Happy days.

However, when I started the car, I started it without the alternator belt on to see if the a/c belt was seated properly and adjust the tension etc.
I noticed I had on the dash, along with what I think was a fairly rough idle :

Battery light (fair enough as alternator belt was off)
CEL light
Rear diff temp light (WTF lol)

I have had these same lights before, several years ago when my alternator terminal bolt was loose. Tightened it and all lights went out upon start up.

Anyway, I switched the car off, put the alternator belt back on.

Started the car, and only the CEL stayed on....for about a 10 mile drive and then for a few cold starts the next day. It then went out.
I took it to my garage of choice, he mentioned a stored fault of "Lean system bank 1" or similar, and put blame on the front 02 sensor - the one where the pale blue wire goes to near the boost control valve on the drivers side turret.

However, he can't remember what the actual code was. These 02 sensors aren't cheap.
My question is this, shall I just get a new 02 sensor fitted as it's toast and hope for the best, or maybe the sensor is fine and it's picking up on another issue?

I haven't seen the CEL light since in about 200 miles.
Any suggestions as a starting point?

My other observation is that inside the exhaust tip looks darker / blacker...maybe more fuel is now being chucked into the cylinders?
But, no CEL since (200 miles)

Vxr2010

if you have had no codes come up in 200 miles then that sounds good , i would still for peace of mind get it plugged in and see if there are any codes still hidden in the system , then you know if it’s not showing any issues then job done , if the ac belt and pulley fail it can puncture the timing casing and take out the cambelt so sounds lucky

Hawkeye D

Jeez! Wow, it was noisy for about a month or so, and always thought "yeah I'll do that at some point"
Nice kit from ICP, everything but the bracket which I cleaned up.

Vxr2010

good to hear it went well , it’s quite a quick job to do , i thought the noise i had was the ac compressor , but found out it was the pulley , then Richard at FB tuning said , if they fail it can sometimes trash the engine as it breaks the cam belt , so i did my other two scobbies as a preventative , it’s similar issues with the ps pump , a change of the rubber seal for 6£ can stop a lot of issues , the top pipe to the reservoir can go hard and leak so again a bit more preventative maintenance

Hawkeye D

Thank you vxr, will keep an eye on that too.