cole_ford

cats should last the life of the vehicle. if you dont get the other problems fixed, you may end up wrecking the cats prematurely. which can be a hefty bill too.(bro just had it happen to his, about 300 bucks to do it himself). they all seem to be on the same page, i would try what they said, before you do more damage.

maurice

Did anyone come up with a solution for this problem?
My 03 4.6 has the exact same problem codes and everything.
I just had the heads done.
Could they have messed up something when doing the heads?

Xan Zenn

Yes, they could have. I found my problem.

Head leakage (coolant) into cylinder causing misfire.

maurice

I had both the gaskets replaced and the heads surfaced. Also had the chains, tensioners and guides replaced. Did you have these replaced when you had your heads done?

Good old Bill

Glad you've got your problem fixed, nice to get good feedback. Helps everyong out.

Xan Zenn

Have not had a chance to pull the head yet. With recession and having a another vehicle I am working every hour I can and will play with the truck when I have time. I am figuring the left bank is my problem.

Was all work done with engine still in truck? I have heard of timing issues when a weak Tech misaligns the gears.

I would start with the easiest. Verify you have spark to cylinders, working your way back to ignition coil making sure plug wires are to correct cylinders. I have also heard new chains can stretch also. Have you had any unusual noise?

maurice

The mechanic hooked the engine up to the computer and the problem was #5 misfire. Ended up being a bad coil. Replaced that and now it runs fine.

thunder0002

it seem like you have the truck running miss fire for sometime; more likely the catalytic converter got melted internal and clogged up inside this created too much back pressure that is why the truck lost power especially at higher RPM. Remove the exhaust, and restart the engine to see the problem go away before you replace it. It will be VERY LOUD!!! WITH OUT THE EXHAUST.

lilbirdierobin

I have had the same problem with my truck ....have you found any answers yet???

lilbirdierobin

Hello everyone..I am new to this site I have a 2006 f150 ftx fx 4x4. I also had the codes 170 175 show up..I have already replaced all the plugs and coils. It still runs terrible... I have no power and was told that if I replaced the maf that it would solve that problm...has anyone else been able to fix this issue yet???