Had a service engine light that would always come on after a couple miles of driving. Obd1 Code read driver side 02 sensor. However the car always ran great for years. I finally decided to replace it and it runs terrible and trips service engine light randomly. Ironically when the light comes on, it run better. I purchased a Denso o2 which was suppose to cross ref , but I am guessing it is NOT right at all. The only Number I could read on the original
o2 is a number 327? It has hooker headers and a Borla dual exhaust and has been a strong running car since I bought it in 2009.
Not sure if I could order stock GM AC Delco or because of the exhaust mods that were done by prev owner I need special O2 sensors.
Also should I replace both.
Also looking on EBAY, they look very similiar to the stock AC Delco .
Thanks

 

I run Denso 234-4012's , no problems.