Newbie here, great site with a lot of information! Just the past week I had my spark plugs changed along with a transmission oil/filter change. Truck drove great. The following day, I got on the highway, went a couple miles and the engine started sputtering and I lost all throttle. I pulled to the side of the highway, wrench comes across the screen and the truck dies. It restarted fine and drove 15 miles home with no problems. Take back to mechanic and he said it showed a Catalyst below threshold code. Checked everything and said they couldn't find anything. Code cleared and later in the week I drove the truck to work as I will be on the highway at 75 mph for at least 50 miles. Drove fine, and while I was on my way home from work, the orange engine light popped on. Took back to mechanic and it pulled the same code. Cleaned the sensor in the air intake and the air filter was dirty so it was changed. Left truck hooked up to computer, checked all cylinders, exhaust and everything checked out okay, which he said was strange, since I got the code again. Mechanic suggested a fuel treatment and high test gas to clean the engine out as the old plugs were not in the best shape when changed. Is there anything else I should look into as I will be leaving soon to head to W.V. towing a trailer full of atv's and do not want any issues. Thanks for the help!

 

Strange it happened just after the work was done and the plugs were changed.

 

That's what we thought. All plugs were firing correctly and checked to make sure nothing was knocked loose.

 

Couldn't that code mean one of your cats is clogged? That issue has caused drive-ability issues on the 6.2.

 

Exactly what I was thinking Rain. This seems to be the biggest issue we have. I know ford recommends plugs at 100k, but with the number of bad cats we are seeing and some people's % of misfire on plugs with 50-100k, I'm wondering if plugs should be changed sooner. If this is the biggest problem we have, we are golden.

To the OP, is there a reason you changed the plugs at 75k? Were you having misfires?

 

Was the work done at a Ford dealership?

 

Any update dingus34?

 

TROLL ????

 

2 total career posts, both in this thread, possibly but I will remain hopeful for a legitimate answer.

 

I apologize I didn't get back sooner as family duties and running the kids around took up a bunch of my time and I didn't have my profile set up to send me email notifications (my bad). I appreciate the responses.

I decided to change the plugs as I was going to trailer some atv's to West Virginia and I usually don't like to wait till 100K to change the plugs. Autolite plugs were initially installed, but changed those plugs out with oem Motorcraft plugs and still got the code. Mechanic suggested taking the truck to Ford since it appeared to be the catalytic converters and would possibly be covered under warranty.

I made an appointment with Ford and did some additional checking. Checked the cats after the truck was warm and found the exhaust temp going in the cats ranged anywhere from 260 to 400, depending if I had it idling fast. The temp going out of the cats ranged from 240 to 320 going out. Sometimes I could hear a rattle coming from the cats and sometimes I could not.

Took my truck to Ford and they confirmed both cats were bad and needed replaced at a tune of $1919.56. Ended up the gal on the phone initially told me my truck was still under warranty, but when she called me to give me the news, the truck wasn't. I told them I appreciated their help, but I would replace them myself. Ford didn't charge me the $100.00 for the diagnosis. Two cats, four O2 sensors, studs, and nuts are on order.....for $900.00.

 

Good to know, thanks for the update.

 

Good to know issues are fixed, but I'm curious ....

What caused the cats to go bad in the first place? 75k miles for two bad cats is not good. I've seen some cars go a lifetime on the OEM cats, and most would last 2x that 75k miles distance easily.

Are bad cats a thing with the 6.2L engine? If so, why?

New cats is treating the symptom. I want to know the root cause of what I'd call premature failure.

I am not as familiar with these trucks as most of you.
Are they undersized?
Does the engine spew way more particulate than other motors?
Where are the cats located? Are these right up at the exhaust manifold? That is common nowadays to get them to fire off quicker, but it also causes things like fouling from frequent cold starts (lots of raw fuel makes it's way into cat due to close proximity to the cylinder) ....

Ideas?


.

 

They are pretty close to the manifolds, not sure if this is a frequent problem, but we've seen it on here before. I would guess maybe it has more to due with poor fuel quality and or driving conditions.

 

I have 411,000 on my truck. Original cats. Go figure.

 

We have a 6.2 here at work with 12k on it. Truck shop is putting cats on it right now. The truck probably has 1000 idle hours though and we have bottom tier gas here in the plant.