Cat Coverter or O2 sensor
Thread Starter
|
New User
Joined: Jan 2006
Posts: 3
Likes: 0
Cat Coverter or O2 sensor
Have a 99 Ford F-150, 5.4L. Engine check light came on. Went do dealer and was told codes revealed bad Cat Coverter and recommended both coverters and all 02 sensors be replaced; however they advised to send it to someone else, because Ford would charge too much for repair.
Went to exhaust shop and they tested air flow. No problem. They said Cat Coverters were good. Must be O2.
Called Ford back and they said no, it is converters but both converters and all 02s need to be replaced to clear check engine light.
Called another Ford dealer and they said they dont automatically replace 02s with converters.
Need help. I already have $80 in this for getting checked by ford. What should I do to save money?
Truck is running good, no problems. Is there a way to disconnect cpu from exhaust Converters, that way light goes off, and will come back on if a different problem exists.
Went to exhaust shop and they tested air flow. No problem. They said Cat Coverters were good. Must be O2.
Called Ford back and they said no, it is converters but both converters and all 02s need to be replaced to clear check engine light.
Called another Ford dealer and they said they dont automatically replace 02s with converters.
Need help. I already have $80 in this for getting checked by ford. What should I do to save money?
Truck is running good, no problems. Is there a way to disconnect cpu from exhaust Converters, that way light goes off, and will come back on if a different problem exists.
Senior User
Joined: Mar 2005
Posts: 113
Likes: 0
How many miles on your truck?
How did the exhaust shop know the cat was good? Just becuase its not restricting air flow doesn't mean its good. Cats don't last forever and when they fail they stop oxidizing/reducing the exhaust gasses. THis is what sets the codes. The O2 sensors can detect when the cat is working or not. If the signal from the front and rear sensors looks the same than your cat is not doing its job and codes will be set.
They are probably hesitant to put a new cat in and leave the old O2 sensors since the sensors will go bad eventually too. If your truck is high mileage than you may want to just replace the sensors as well. Theoretically you shouldn't have to but if you plan on keeping your truck for a while it may be a good idea. Your call.
As tempting as it is, don't disconnect your O2 sensors. You'll have poor fuel control, high emissions, possibly poor fuel economy, and your check engine light will stay on forever.
How did the exhaust shop know the cat was good? Just becuase its not restricting air flow doesn't mean its good. Cats don't last forever and when they fail they stop oxidizing/reducing the exhaust gasses. THis is what sets the codes. The O2 sensors can detect when the cat is working or not. If the signal from the front and rear sensors looks the same than your cat is not doing its job and codes will be set.
They are probably hesitant to put a new cat in and leave the old O2 sensors since the sensors will go bad eventually too. If your truck is high mileage than you may want to just replace the sensors as well. Theoretically you shouldn't have to but if you plan on keeping your truck for a while it may be a good idea. Your call.
As tempting as it is, don't disconnect your O2 sensors. You'll have poor fuel control, high emissions, possibly poor fuel economy, and your check engine light will stay on forever.
FTE Leadership Emeritus
Joined: Jan 2003
Posts: 161,999
Likes: 75
From: 3rd Rock
Originally Posted by greentrooper
Have a 99 Ford F-150, 5.4L. Engine check light came on. Went do dealer and was told codes revealed bad Cat Coverter and recommended both coverters and all 02 sensors be replaced; however they advised to send it to someone else, because Ford would charge too much for repair.
Went to exhaust shop and they tested air flow. No problem. They said Cat Coverters were good. Must be O2.
Called Ford back and they said no, it is converters but both converters and all 02s need to be replaced to clear check engine light.
Called another Ford dealer and they said they dont automatically replace 02s with converters.
Need help. I already have $80 in this for getting checked by ford. What should I do to save money?
Truck is running good, no problems. Is there a way to disconnect cpu from exhaust Converters, that way light goes off, and will come back on if a different problem exists.
Went to exhaust shop and they tested air flow. No problem. They said Cat Coverters were good. Must be O2.
Called Ford back and they said no, it is converters but both converters and all 02s need to be replaced to clear check engine light.
Called another Ford dealer and they said they dont automatically replace 02s with converters.
Need help. I already have $80 in this for getting checked by ford. What should I do to save money?
Truck is running good, no problems. Is there a way to disconnect cpu from exhaust Converters, that way light goes off, and will come back on if a different problem exists.
We are happy you have chosen the best source for Fords!
Enjoy FTE....and
JOIN CLUB FTE -SUPPORT THE FORUMS!
…..See you on the boards.
Senior User
Joined: Jan 2004
Posts: 141
Likes: 0
From: Rockford, IL
Did they tell you the dose numbers?? If it's something like Catalytic Inefficiency then your converter is not doing its job and needs to be replaced. They try and sell you O2 sensors to try and cover their butts and just incase they don't come out of the pipe nicely. I toatally agree with above statemant tho... with a lot of miles, you probably should.
Elder User
Joined: Dec 2004
Posts: 675
Likes: 0
From: Springfield, OR
On a 99 your cats should be fine unless your mileage is extreme. I would replace the O2 sensors and reset the check engine light. the O2 sensors usually give out before the cats. You cant drive the car without the O2 sensors cause all air/fuel ratio is determined from those sensors. If you have been driving the vehicle a long time with the sensors bad you can clog the cats with deposits.
Thread Starter
|
New User
Joined: Jan 2006
Posts: 3
Likes: 0
Trending Topics
Posting Guru
Joined: Jul 2004
Posts: 1,479
Likes: 4
Based on my last Ford vehicle and others that have owned them, I would bet it's only the O2 sensors! Seems like 85 to 100K miles is the magic number for Ford O2 sensors to fail! If you drop the codes it will tell you which one is failing. Get the code from the dealer! I will also say after replacing the one pointed out by the code the others will soon follow behind!
You can reset the light 2 ways, either with a code reader you can get from your auto store or by disconnecting the battery. Be aware that by disconnecting the battery your PCM will have to relearn your driving and engine characteristics. So for the first hundred miles or so you may notice a change in idle, and or performance up until it relearns.
You can reset the light 2 ways, either with a code reader you can get from your auto store or by disconnecting the battery. Be aware that by disconnecting the battery your PCM will have to relearn your driving and engine characteristics. So for the first hundred miles or so you may notice a change in idle, and or performance up until it relearns.
Last edited by KevinM; Jan 10, 2006 at 09:58 AM.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Senior User
Joined: Mar 2005
Posts: 113
Likes: 0
If you find out exactly what the codes are:
If only the cat efficiency codes - than most likely your cat is bad.
If only the O2 sensor codes - than your sensors are bad.
If O2 sensor codes & Cat efficiency codes - than it MAY only be your sensors.
If only the cat efficiency codes - than most likely your cat is bad.
If only the O2 sensor codes - than your sensors are bad.
If O2 sensor codes & Cat efficiency codes - than it MAY only be your sensors.