Catalytic problems?
Thread Starter
Junior Member
Joined: Jun 2012
Posts: 3
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Catalytic problems?
Hey All! First post!
I have a 2002 Ford F150 FX4 5.4l. I have had the dreaded knock and tick, but I think i cured the tick. Apparently using Motorcraft oil filter and Oil makes a huge difference!. I go for regular oil checks as I should, but just using the wrong stuff. That made the "ticking" go away.
What I'm concerned about is the 'knock'. I've read literally hundreds of forum posts about this dreaded knock. But diving deeper into each, I fear the 'knock' is different in each scenario.
I've been trying to diagnose this for years, and it has been to 2 different Ford Dealerships - all with different answers. I've heard everything from "piston slap" "rod knock" "loose bearing" right to the engine noise resignating through to the "Light off" converters??? Once the engine warms, and I'm moving - the truck is quiet, purr's like a kitten and no sound is heard. This sound has been heard for years with no apparent damage, the sound isn't getting stronger nor weaker.
The sound is mostly heard comming from the cat's. I heard that there was a TSB, and to get this $500 wrap to wrap the light off converters (sp) to hide the noise and bandaid the solution.
I'm just wondering if it's the cat's or the pre cats (light offs?). Here is the problems I've been experiencing.
I had the engine light come on. I ran the code, and it was the Mass airflow sensor. I checked it out, and it seemed fine so I bought the cleaner and the light went out. It started to run and idle funny just before the light came on and after. After about a week or so, the light came on again, and this time it was the O2 sensor. Bank 1 Sensor 1. So I changed all 4. The light went out and never came back on. The truck always idled weird. When I first start it, it sound like it would idle, then drop, then idle and drop bouncing from 1500 to 600 rpm for about 5 repetitions.
I have noticed a decrease in power, but I can hardly spin the tires on gravel, but I have no problem reaching speeds of 100km/hr or more. The truck has been through times where it has been rough to start - (Noticed more in the cold Canadian months).
Now, when I throw together - Loss of power, rough idling, blown o2 sensors, MAF sensor problems. It leads me to believe that it could be a cat problem. One muffler shop said they can do a vacuum test but will not touch my cat's. Obviously for a price.
I don't have a tonne of cash for a bunch of "what if's" so I was hoping to seek help from you guys? So what do you think?
Knocking could just be the TSB problem reported by ford?
Loss of power and cold rough idling be a cat problem?
Thanks in advance!!
I have a 2002 Ford F150 FX4 5.4l. I have had the dreaded knock and tick, but I think i cured the tick. Apparently using Motorcraft oil filter and Oil makes a huge difference!. I go for regular oil checks as I should, but just using the wrong stuff. That made the "ticking" go away.
What I'm concerned about is the 'knock'. I've read literally hundreds of forum posts about this dreaded knock. But diving deeper into each, I fear the 'knock' is different in each scenario.
I've been trying to diagnose this for years, and it has been to 2 different Ford Dealerships - all with different answers. I've heard everything from "piston slap" "rod knock" "loose bearing" right to the engine noise resignating through to the "Light off" converters??? Once the engine warms, and I'm moving - the truck is quiet, purr's like a kitten and no sound is heard. This sound has been heard for years with no apparent damage, the sound isn't getting stronger nor weaker.
The sound is mostly heard comming from the cat's. I heard that there was a TSB, and to get this $500 wrap to wrap the light off converters (sp) to hide the noise and bandaid the solution.
I'm just wondering if it's the cat's or the pre cats (light offs?). Here is the problems I've been experiencing.
I had the engine light come on. I ran the code, and it was the Mass airflow sensor. I checked it out, and it seemed fine so I bought the cleaner and the light went out. It started to run and idle funny just before the light came on and after. After about a week or so, the light came on again, and this time it was the O2 sensor. Bank 1 Sensor 1. So I changed all 4. The light went out and never came back on. The truck always idled weird. When I first start it, it sound like it would idle, then drop, then idle and drop bouncing from 1500 to 600 rpm for about 5 repetitions.
I have noticed a decrease in power, but I can hardly spin the tires on gravel, but I have no problem reaching speeds of 100km/hr or more. The truck has been through times where it has been rough to start - (Noticed more in the cold Canadian months).
Now, when I throw together - Loss of power, rough idling, blown o2 sensors, MAF sensor problems. It leads me to believe that it could be a cat problem. One muffler shop said they can do a vacuum test but will not touch my cat's. Obviously for a price.
I don't have a tonne of cash for a bunch of "what if's" so I was hoping to seek help from you guys? So what do you think?
Knocking could just be the TSB problem reported by ford?
Loss of power and cold rough idling be a cat problem?
Thanks in advance!!
Senior Member
Joined: Mar 2013
Posts: 2,106
Likes: 235
From: Fullerton, CA
I believe you have identified the issue. The cats can build up carbon due to poor fuel/air mixtures. Once they heat up, enough carbon is burned off for them to flow exhaust correctly. Everything you have corrected points to a partially plugged cat.
You can try a fuel additive which will help clean them after about 100 miles of driving and it may fix it for good. Try SeaFoam. If the problem continues, I would get the pressure/flow test done before shelling out a ton of cash for new cats. In California by law we have to use "OEM Ford only" cats and they are costly. Good luck
You can try a fuel additive which will help clean them after about 100 miles of driving and it may fix it for good. Try SeaFoam. If the problem continues, I would get the pressure/flow test done before shelling out a ton of cash for new cats. In California by law we have to use "OEM Ford only" cats and they are costly. Good luck