When my Crown Vic had a bad o2 sensor the CEL would only turn on like once a week then turn off but the code was always there...

 

Thanks Jay, My cel only comes on during start up but has never shown a fault. Have you had any experience with what the dealer scanner will show, will it pin point a particular cylinder?

 

I had that pooping sound for almost 4 years. Got new intake filter, cleaned the sensor inside the intake , new 10 coils, new sparks , cleaned injectors, engine carbon flash. ,o2 sensor .
But it's still there , so I ignore it .

 

Hey Mr... By popping I'm reading your suggesting like a popping back through the, as an oldtimer I would say carb but through the throttle body. If so I would suggest might be a valve maybe hanging up which a compression test would prove. Specially as you've change everything else.

Mine is a slight hesitation with a loss of power every now and again with no popping or anything. Happens at low around 30 mph and a simple kick on the throttle gets it going again.

 

The test which needs to be run is the Cylinder Contribution Test. A shop which has a Snap On scanner with the latest software will be able to run the test and see if any particular cylinder is performing below the others. The data is live and can be graphed to capture the information on a test drive and saved for review.

 

I don't have any loss of power or hesitation. Only in a stop I can feel a tiny tiny shaking.
But I'll check the compression after I fix my o\d flashing.
I got the truck from ford service, for hours and they said every thing is in perfect condition , and they did a transmission wiring harnesses fix , but flashing and slamming 1,2 gears appears after a short drive .

 

Cylinder Contribution Test is exactly what I need, being able to run the test underway is perfect. Maybe I'll check with local Snap-on dealer to see who has one, totally worth the cost. Thank you...