Think one of the injectors may be going bad. Car finally ran on all 8, and ran strong for about 10 miles. Then one bank started running leaner, and the other bank rich. Has a definite stutter, like one cylinder is't hitting. Spark is good, and NO codes. Maybe an injector? Is there any way to test? Or is there a better way to determine what's going on? FPR maybe going bad? How to test it on a 93?

 

You can't tell if the FPR is bad while the engine is running. The FPR is checked with the engine off. Also it effects start ups, not running.