Thread: Misfire #6

Have a Misfire code and the Fuel Inject code on my 1999 Grand Prix (3.8).. I replaced the injector, did a full tune up, wires, plugs, fuel injecting cleaning, and even a tranny filter and gasket change. After a day or so, it started to run rough and threw the same codes..... I was reading that sometimes it can be a ground issue.... I can say that the main ground going from the batter to the car was poor.... it was grounded to a painted surface.... I corrected that ... Now my Low Coolant light came on.... well kinda off and on... now on all the time.... I replaced that module in March..... plenty of coolant and levels are good.... its acting like a ground... can anyone tell me where the main harness ground for the Low coolant module is?????

I didn't move the ground.... I just unscrwed the cable and cleaned it up. Ill see if I can get a pic.... It terms of the coolant light... I will remove/clean/replace, but it really acts like an electrical problem... Light doesn't stay on... it fades in and out... very strange.... Thanks for the suggestions... The code was PO206---- the other code was a 300 code..... Misfire on #6... same as my fuel injector

The scanner I have identfies the cyl. It was confirmed byt dealer

Test resistance across the injector. Should be around 15 ohms.

Originally Posted by rnpiii

The scanner I have identfies the cyl. It was confirmed byt dealer

P0306 is cyl 6 misfire.

Y’all are correct PO306 and I test the injector... was week... cleaned the connector and put a small amount of electrical grease... then test correctly.... did that this am... dove 20 miles and so far so good........

Everything working fine. Since the rewiring, the motor runs as it should & has not produced a code.