Have a 2007 F150 5.4 V8, the CEL was on and the repair shop said I needed to replace both catalytic converters and the down stream O2 sensors about $1700 including labor, I said not now. I drove about 60 miles and the light went out, it has done this before, never flashed or anything just stays on. Truck runs fine but has 198,260 miles, does this sound like a converter problem?

 

Welcome to FTE dewey47,

We canʻt say that it IS a cat problem without you posting the actual codes.

At nearly 200,000 miles (if not a typo), what could be in question are

the O2 sensors.

Also, we donʻt know how the truck was cared for over the past 6 years.

When was the last tune up. plugs, cops, filters, etc.

Posting more information from you will aid in a COMPUTER SCREEN diagnosis.

 

No- I would R&R the O2 sensors as their life span is typically 100k miles

 

Don't take it back to that shop. You always replace upstream sensors when you replace a cat. You would only ever replace the downstream ones if you had a code indicating they were bad.

I would start with replacing the upstream O2 sensors, they are way overdue for replacement.

What about your other tune up items? Make certain you are up to speed on all maintenance items outlined in your owners manual. If you are overdue, get it done. Also run a carbon treatment through your intake, carbon deposits can cause cat problems, and/or contribute to inaccurate sensor readings.

 

Thanks, I had coils 8-3-7-2 replaced Sept 2012 and the plugs and wires replaced Oct 2012 at Ford dealer, the CEL didn't come on until 30 days or so after the plugs and wires were changed. Runs fine no miss even at max acceleration, any ideas on what brand of carbon treatment?

 

Seafoam is my personal favorite, BG44k is a good one too. Moot point though if you have bad O2 sensors. I would start with those, they are way overdue.