Mercury Mountaineer error code PO204, injector circuit open cyl 4

meatbkr

i recently replace the coil on plug on cyl 4, and it never did run much better, rough idle and some acceleration hesitation.sane as before the repair, the first code that came up was PO304 misfire on Cyl 4, then i replaced the coil and plug , after a week i got the code pO204, is they a fix for this on my 8 cyl. mountianeer.

Mr_Shiftright

You could have an open circuit in that fuel injector, or a bad fuel injector, or worst case, a defect in the PCM module. Further testing would be required to pinpoint which one. But code 204 would certainly account for a misfire, and also throw you off into replacing parts that weren't necessary it sees.

meatbkr

so check the fuel injector first, right, is there any injector cleaner that might work

Mr_Shiftright

I'd test for electrical impulse first using a simple NOID light. No pulse, no injection. Maybe you could look carefully at the wiring for that injector and spot some fray or broken wire or ???

meatbkr

OK, thanks for the leads

Mr_Shiftright

Here's a tip:

http://www.youtube.com/watch?v=GDJoKIoSd-w

meatbkr

thank you, that my kind of tip, nothing to buy