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Juan Crespo
Juan Crespo, Tech Trainer
Category: Ford
Satisfied Customers: 1500
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
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No. 2 cylinder misfire code. removed and replaced injector

Customer Question

no. 2 cylinder misfire code. removed and replaced injector and fuel line. little smoke from exhaust every 5 minutes. does computer need to be reset to eliminate existing code?
Submitted: 3 months ago.
Category: Ford
Expert:  Juan Crespo replied 3 months ago.

Hi there.

I assume you're talking about code P0302. If so, it will stay off after erased with a scan tool as long as the condition that caused it has been repaired.

A misfire code will set when the ECM detects the crank slows down as it's being rotated by a particular cylinder. This could be caused by several things, not just a bad injector. That, plus the puff of smoke makes me wonder if there is something more involved, like valves. Can your scan tool do balance tests? If so, could you share the results?

Customer: replied 3 months ago.
small scanner can't balance. could it be possible compression issue?
Expert:  Juan Crespo replied 3 months ago.

Yes, that's what I mentioned valves as being a potential problem. Without the proper scan tool, things get much harder to diagnose, but not impossible. Can you do a cylinder leak-down test? (much easier than a compression test)

Customer: replied 3 months ago.
also other driver involved when it happened. I was on holidays.mysteriously some fluid from that side unexplained. found no leaks other than a cracked intercooler hose,and a loose valve cover bolt. no antifreeze missing and still clean oil, not contaminated.have a compression tester. that's about it.
Expert:  Juan Crespo replied 3 months ago.

Then it looks like the compression test is your only alternative. Remember, you're not looking so much for an exact pressure, but for a big discrepancy as compared to the other cylinders.

I'm about to log out for the day. Please post the results and I'll check on them as soon as I log back in at 2 PM EST.

Best Regards.

Customer: replied 3 months ago.
thanks. not really what I wanted to hear but all s--t runs downhill and I am skiddin fast.....great truck to drive but 400,000k's second motor trouble is brewin...great help thanks again!!!!
Expert:  Juan Crespo replied 3 months ago.

I just reread your post about how it had happened when you were on Holiday - that really stinks...

Best Regards.

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