So a few days ago i went to downtown seattle and when i got back to my car i start it up and the CEL came on. It wont rev past 3k rpms but im pretty sure because its in safe mode. I checked my ecu and it flashed 6 times at me and i looked at the diagnostics for a obd0 ecu and it said bad Engine Coolant Sensor. so i went to napa today and replaced it but the problems still exists. what else could it be? PLEASE help.. its really starting to irritate me. thanks.

 

there i more than one coolant sensor and did you replace both?

 

Obd0? Is this a B20A5 or B21A1? Which B20 are you talking about?