Catalytic Converter???

[sday]

I've had the worst luck with my 2005 SR5 lately. It was throwing a cylinder 6 misfire code. I got new plugs at Advance Auto, then installed new coil packs. It still wasn't running right. 2 days later I had it towed to a shop (I used to trust) because it was running horribly and the CEL was flashing up a storm. This shop told me I might have a blown head gasket, pistons might be damaged...$1500 to figure out what exactly was wrong, maybe $3000-$6000 for repairs. I left there crying.mobile mechanics checked it out and after 2 1/2 hrs they decided that the original shop people were on crack but they still didn't know what was wrong with it.They tried a new fuel injector and that didn't work either. I took it to the dealership where I was informed that Advance sold me plugs that were way too small which was causing the misfire. It also screwed up one of my new coils. Oh boy! I finally received my new coil and installed it with my dad. FINALLY, Jaws was running beautifully. I took it to the dealership the next day to have the lights reset. I filled up with gas the next day and boom...the lights are back on and the mileage thing that normally says 435 miles left until the next fill-up still says 100 ish less than that. During this whole ordeal it was getting about 100miles less per fill-up than before. Back to the dealership I went and now I am told that I need a new catalytic converter. They claim that due to the plugs that ruined my life, excess fuel wasn't burning right and it clogged up my cat. Of course I am not going to let them repair/ replace the cat since it's costly. How many cats are there in my 4runner and how do we know which one to fix?

Thanks!
Sarah

 

[BlackWorksInc]

Hi Sarah,

There are 4 catalytic converters on a 4th gen 4Runner. 1 Pre-Cat and 1 Post Cat for each cylinder bank, the Pre-Cats are built into the exhaust manifolds.

First and foremost, do yourself and your father a favor and see if you can get the DTCs that the multiple shops pulled from the vehicle (they should be provided with your copy of the Repair Order as a "Health Check.)

If you have at least the DTCs from this most recent trip to the dealership where they are recommending Catalytic Converters, we can at least try to narrow down the possibilities and gain a better idea of what could/is damaged on the vehicle and whether or not the Catalytic Converters do need to be replaced.

If you also take some time to read through the "Catalytic Converters & P0420's" section of this thread: http://www.toyota-4runner.org/4th-gen-t4rs/132953-toolbox-how-use.html#post1272379

It may help you get a better idea of what the dealership is talking about and how we can help you determine what the possible issue(s) is at the moment.

 

[scw1991]

I owned an older 80's vehicle at one time with a plugged up catalytic converter and the vehicle had no power if this is any help in diagnosing potential repairs.

 

[MikeInNH]

It's a possibility. But usually when a cat is bad then the downstream O2 sensor will detect it and throw a code.

The bad spark-plugs could have caused the cat to fail. I'm just concerned that there's not a code thrown.

If it is a cat...you do NOT have to go with and OEM cat. There are several aftermarket cats that work perfectly well.

 

[radlynx]

seems to me it's a headgasket issue. if you search in here, you'll find a lot of people with cylinder 6 misfire and fixed it by replacing the cylinder head gasket.

I've had the worst luck with my 2005 SR5 lately. It was throwing a cylinder 6 misfire code. I got new plugs at Advance Auto, then installed new coil packs. It still wasn't running right. 2 days later I had it towed to a shop (I used to trust) because it was running horribly and the CEL was flashing up a storm. This shop told me I might have a blown head gasket, pistons might be damaged...$1500 to figure out what exactly was wrong, maybe $3000-$6000 for repairs. I left there crying.mobile mechanics checked it out and after 2 1/2 hrs they decided that the original shop people were on crack but they still didn't know what was wrong with it.They tried a new fuel injector and that didn't work either. I took it to the dealership where I was informed that Advance sold me plugs that were way too small which was causing the misfire. It also screwed up one of my new coils. Oh boy! I finally received my new coil and installed it with my dad. FINALLY, Jaws was running beautifully. I took it to the dealership the next day to have the lights reset. I filled up with gas the next day and boom...the lights are back on and the mileage thing that normally says 435 miles left until the next fill-up still says 100 ish less than that. During this whole ordeal it was getting about 100miles less per fill-up than before. Back to the dealership I went and now I am told that I need a new catalytic converter. They claim that due to the plugs that ruined my life, excess fuel wasn't burning right and it clogged up my cat. Of course I am not going to let them repair/ replace the cat since it's costly. How many cats are there in my 4runner and how do we know which one to fix?

Thanks!
Sarah

 

[sday]

The original shop said the following codes: PO300, PO305, and PO306. After I had the second opinion they did not get any codes besides cylinder 6 misfire. I'm going to swing by Auto Zone on my way home and get them to use the code thing and see what they say. Sorry I don't know the technical term for the code thing! By the way, after the horrible diagnosis by the first shop, when I took it to the dealer I told them nothing about the head gasket, piston problem I was orignally told. I didn't want to give them any ideas. They just said the wrong spark plugs caused the whole issue and once the coil and plugs were replaced everything was ok until the lights came back on the next day. The service advisor told me it was the cat but didn't write anything up (I'm assuming to avoid having to charge me another diagnosis fee). We'll see! This has not been a very fun experience.

 

[sday]

I'm going to get the codes read again on my way home today...not at ADVANCE!