Catalytic Converter Replace Suggestion (2001 4cyl)

[cltmmm]

I feel like an outcast... I cannot find any information on how or where to get a bolt-on (not weld on) cat converter for my 2001 4 cyl Highlander. There are a ton of websites with 6cyl models. I found one with an overpriced one for a 4cyl version. My Haynes manual is highly lacking in explaining anything about how many cat conv there are, and if I am throwing a 0420/0430 codes, which one to replace.

Does anyone have any suggestions on where to find a rebuilt or aftermarket conv for a 2001 4cyl Highlander? OEM is just ridiculous... The dealer wants to charge me more than the vehicle is worth.

[asianflava]

Ours were replaced by the dealer a couple years ago, Yay extended warranty!
Good luck!

[bepperb]

I have an 04, so I can't say for sure, but at least on ours the first catalytic converter is the same thing as the exhaust manifold, which explains why the manifold costs 450 bucks at toyotapartscheap.com. I might email them to verify that this is the manifold/converter, and buy it there. You'll also need a new exhaust manifold gasket, a can of PB blaster, and an impact wrench or a good length breaker bar (or a cast iron pipe over your ratchet).

I'm not sure how to determine which cat is bad, sorry. But, from the manual it doesn't appear that there is an O2 sensor after what looks like the second cat. So my assumption would be that it's the first.

The actual name on the diagram is "Exhaust Manifold Converter Sub Assembly". If you want some .pdf's, I can email them to you.

[ddvk]

cltmmm:

Diagnosing the root cause of P0420/P0430 is almost the most difficult thing in the ODB2 codes. Manufactures map all emmision issues like O2/pre-cats/cats onto these 2 codes.

Hoping you are doing some basic maintaince like plugs, air-filters, fuel-filter and basic tuneups to injectors... Lets start to understand ur issue...

1) Have you ever replaced your O2s? If you haven't I would start there...
2) Have you ever smog checked your vehicle? If not needed in your state, then run a basic exhaust test with AAA and check the numbers vs averages. You will be surprised the pre-cats/cats work just fine..

BTW, cats/pre-cats usually are designed for the life of the car (I didn't say that, that is what the manufacturer says), but I would be surprised you fouled the cats/pre-cats with poor gas and maintainence...

Finally it boils down the maintaince, poor maintainence on plugs, filters, tuneups will foul the O2 sensors and eventually the pre-cats/cats...

I would start replacing the O2 sensors, if you haven't already done that along with plugs and filters. Good luck you have your hands full with these 2 codes.!!!

[cltmmm]

Thanks for the reply, and sorry for the delay. I lost track of the forum...

A quick background of the vehicle. I bought it used from a shady dealer (found that out later he was a scheister). It had 67k miles on it and it threw an O2 sensor code after I got it home. I replaced one bad O2 sensor. About 200 miles later it started throwing the 0420 and 0430 codes. When I took it into the dealer, they said I need a new converter. I don't know how much I believe them...

I SeaFoamed the engine through the vacuum system and it got rid of the code for about 2,000 miles. Now it is back with a vengeance. I put 50k miles on a year so I am at 170k miles now in two years and need to get the car inspected (emissions are tested).

My thought is they ran it with a bad O2 sensor so long they burnt out the cat. I have SeaFoamed it again, but it no longer fixes the problem. I am wondering if changing all the O2 sensors will help if the cat is bad anyways...

In any case, what is a good O2 sensor to get on the cheap?

Thanks!

[ddvk]

NGK Spark plug, NGK Spark Plug wire, NGK Platinum Spark plug for High Performance and Racing.

I always source my sensors for my vehicles from here. They come with end connectors, no splicing etc. Their prices are 50% lower than the stealerships.

[LifeTech]

Fact: There is not much aftermarket support for the HL 4 cylinders, never was ...doubt there will be... now that the 2nd gen HL's are here 8 years later. This fact reflects the non competive pricing yu will see for 4 cyl. OE cats at various Toyota parts depts and the web. Low production for 4cyl HL's = Low demand for aftermarket engine parts.

And I am a firm believer in OE cats. Experience dictates. Hopefully it is not the cat. It is rare for it to go out. Focus on other sensors first.

What I am saddened with is the excessive use of "Seafoam"!!!:sad:

YU may just have solved nothing with this stuff. Or perhaps even masked or added problems/codes to your dilemma.

Seafoam sucks. Won't touch this stuff. Have seen it used many many times on OPC's. (other peoples cars) It is snake oil... "magically cleans" everything crap. If I'm asked to use on OPC's ...I will decline. I have seen it do more harm than good.
Initially ,I thought it to be a benign product on some cars (a can't hurt product) As of late I have seen it create a mess of the emmissions and intake system. Fouling sensors etc.
Some may just flame me for this statement. Oh well. I'm a big boy!

My sincere honest opinion. I don't mean to hurt your feelings or others here and if I didn't care about your issue I would not have even mentioned it.

LT

[jzack]

2nd on this advice. Do the sensors first, just the ones that haven't been changed out already. This at least verifies they are OK before moving to the cat...

[LifeTech]

Follow jzacks recomendation.

LT