My car stalled out on me twice today, I had the battery checked and recharged at autozone, but it didn't help, the car was idling at ~550 rpm and at a inconsistant 14.0-15.0 AFR. It's a singled 1jz. I changed the spark plugs, and 4 out of 6 had oil on them and they all were fouled. After I changed them, it seemed to be running fine at 13.8-14.2 afr and not spuddering or missing during idle.

Any ideas? or was it just the plugs?

Also, what's the correct AFR for a 1jz single turbo car? I know it needs to be tuned, but I wonder how bad off it is atm.

Thanks.