Flashing CEL

[Jason Cottier]

2012 v6 Explorer Limited. Car was at mechanic for new waterpump and timing chain. No issues with the timing chain we just replaced it as mileage is at 320k.
After I got it back the CEL light was on. FOund my OBD11 reader and the code for bank2 sensor 1 was there. CHecked the sensor and the mechanic had forgot to re-attatch the wiring harness. I did that then cleared the code. Restarted the vehicle and light stayed off. Just took it for a run as the wife is going on a trip.

Car ran rough on acceleration and CEL was flashing. Freaked me out as I have never seen that before. After a couple of miles it quit and light stayed off. Also the car ran so much better! Was wondering if it was the computer re-adjusting? I have heard in this forum of the system learning my driving habits. Since the o2 sensor was disconnected for about 1 month, I was hoping this might be the case.

Any ideas would be grateful as my wife leaves on a 10 hr drive tomorrow and I am a bit worried.

 

[Jason Cottier]

Not much for help on this one. However, I did speak with 2 mechanics, one a Ford Tech. Apparently it is quite probable that because the P0155 code was on for a lengthy time(was disconnected), the long term memory could be influencing the performance. The flashing CEL is for misfire.

Both mechanics said to keep driving and maybe do a tune-up soon. Has never had one. The most likely cause was the reconnection of the O2 sensor and the relearning of the ECM.

Fingers crossed

 

[peterk9]

The vehicle has an Automatic Adaptive Learning Transmission but unless the battery was disconnected or replaced, the learned process should still be in effect. Jason, when you said it has never had a tune-up does that mean you are still running the original plugs?

Peter

 

[Jason Cottier]

The vehicle has an Automatic Adaptive Learning Transmission but unless the battery was disconnected or replaced, the learned process should still be in effect. Jason, when you said it has never had a tune-up does that mean you are still running the original plugs?

Peter

I think so. I bought it at 80kms now have 320kms, I haven't replaced them.

 

[Jason Cottier]

The vehicle has an Automatic Adaptive Learning Transmission but unless the battery was disconnected or replaced, the learned process should still be in effect. Jason, when you said it has never had a tune-up does that mean you are still running the original plugs?

Peter

Just spoke to the wife and the car is doing it again. After heavy acceleration, car misfires, runs rough, light flashes and now stays on. Plugs and boots?

 

[peterk9]

I think so. I bought it at 80kms now have 320kms, I haven't replaced them.

Do you mean 320,000 km? The manual shows to replace them at 160,000 km.

Peter

 

[TXScott]

Would definitely replace the plugs and coil packs at that mileagle (kilometerage? Is that proper Canadian?), and I would only use Ford Motorcraft coil packs. Replace the PCV while you got the upper air plenum off. Also, consider replacing the plenum gasket while youre at it. I dream mine makes it to 320,000 km! Usually it doesn't take long, even only 10-15 minutes, for the battery to be disconnected before all the fuel trim and shift points are lost from computer memory and automatically go into re-learn mode once it's back on the first time. I always, hold the brake down for 10 seconds at first startup, let the throttle body do calibration sweep, THEN hit the button to start the engine. I then let the engine idle for 10 minutes with absolutely nothing else on(radio, air conditioner, etc.) before starting to take it for drive.

 

[Jason Cottier]

Would definitely replace the plugs and coil packs at that mileagle (kilometerage? Is that proper Canadian?), and I would only use Ford Motorcraft coil packs. Replace the PCV while you got the upper air plenum off. Also, consider replacing the plenum gasket while youre at it. I dream mine makes it to 320,000 km! Usually it doesn't take long, even only 10-15 minutes, for the battery to be disconnected before all the fuel trim and shift points are lost from computer memory and automatically go into re-learn mode once it's back on the first time. I always, hold the brake down for 10 seconds at first startup, let the throttle body do calibration sweep, THEN hit the button to start the engine. I then let the engine idle for 10 minutes with absolutely nothing else on(radio, air conditioner, etc.) before starting to take it for drive.

We say mileage even if it's kilometers. I will do everything you suggest...when she gets home. She made the 10hr trip. Light flashed a few times a is staying on now. I'll check codes when she gets home Monday. Why only Ford coilpacks? I have trade pricing at a local parts store but not Ford. I really appreciate your advice, thanks so much.

 

[peterk9]

Hi Jason. When looking for genuine Ford replacement parts I would recommend a site such as this one; Genuine OEM Ford Parts & Accessories Canada --F150 and Mustang | Eastgate Ford Parts CA
I don't know if you have similar sites in Western Canada or not but they sell well below dealer prices.
For those in the U.S. Levittown Ford is a forum vendor and offers members here a discount but I don't know about shipping to Canada.

Peter

 

[TXScott]

We say mileage even if it's kilometers. I will do everything you suggest...when she gets home. She made the 10hr trip. Light flashed a few times a is staying on now. I'll check codes when she gets home Monday. Why only Ford coilpacks? I have trade pricing at a local parts store but not Ford. I really appreciate your advice, thanks so much.

Electrical stuff can get very picky/specific, would sooner go cheap on a filter, accessory or body part than anything electrical. Also, if something electrical shorts for going cheap, the damage to other components can get spendy and tricky.

 

[Jason Cottier]

Just to update, with thanks to all that helped. I did change the spark plugs and pcv valve. The boots and gasket were just fine. There was no brittleness, they looked new. I did replace all my manifold bolts. Had one twist off at 5lbs of torque instead of getting to the 89 inch pounds. So I did not want to take any chances and just changed them all. I did stick with the genuine FOrd parts as recommended by you all.

Also I inspected the plugs as they came out and went in. Number 6 (the one on the code) was about 13 thousandths over gapped and the electrode looked a lot smaller than the new. Factory gapping was accurate. I did notice some oil in the spark plug area under the coil protective cover, not sure if this was from oil change spills or not, so I just cleaned it up and put the plugs in.

The CEL light was gone immediately on start-up and performance is good. No shudder so far. I am thinking of doing the sea foam service n the tranny anyway. Thoughts?? I do occasionally get a exhaust pressure thresh hold light. Always goes away with clearing and stays off, so not sure what that is either.

Thanks so much for the help! Saved me at least $300
Jason