2004 4cyl. Highlander, 89000 miles. Replaced front 0xygen sensor Nov 22. Now have to replace the converter. Is this a common Toyota problem? Thought converters lasted more than 7 years. What will fail next? The snow ball effect is coming, I sense it. More repairs down the road. Help!

2004 4cyl. Highlander, 89000 miles. Replaced front 0xygen sensor Nov 22. Now have to replace the converter. Is this a common Toyota problem? Thought converters lasted more than 7 years. What will fail next? The snow ball effect is coming, I sense it. More repairs down the road. Help!

That sux... and they ain't cheap. Should last you for a long while after the replacement.

Cats and pre-cats are for the life of the vehicle. Check cats are working by running a smog test for $30.

Check your owners manual. Emission's warranty is different than bumper-bumper and power-train warranties. And, even the seat-belt has a different warranty than those three. So, you should look up the warranty for your 'emission system'. Gov't requirements for catalytic's is separate from other warranties.

All it takes is one bad tank of gas to kill a catalytic converter. And, driving excessively with a bad o2 sensor will do the same.
Many failures that I've seen with cat's is when some road debris hits 'em and the insides of the converter break apart.

There is no snow ball effect. Ones driving style and maintenance history have a big say on what fails.

Catalytic converters are not for the life of the vehicle. They are a wear item.

O2s indirectly foul cats eventually over a long time (if one thought O2s are lifetime, they last 80-100K at best) but the biggest culprit to fouling cats is running rich or impartial burn (faulty ignition coils) and offcourse welds falling apart.

O2s indirectly foul cats eventually over a long time (if one thought O2s are lifetime, they last 80-100K at best) but the biggest culprit to fouling cats is running rich or impartial burn (faulty ignition coils) and offcourse welds falling apart.

Guess I am doing good then. Mine are fine after 180k. A friend of mine has a T100 with 300k+ and they are original.

Guess I am doing good then. Mine are fine after 180k. A friend of mine has a T100 with 300k+ and they are original.

Time to replace them and keep the cats/precats happy.
I have seen OEM parts specially cats, motor mounts that are not the same quality as the one that came originally with the vehicle. So preseving the original parts as much as one can is the way to go.

The O2s may cost $400 in all and one recovers that money over better MPG over 1 yr.

I must tell you also that Toyota does really make good products, no doubt about it.

Time to replace them and keep the cats/precats happy.
I have seen OEM parts specially cats, motor mounts that are not the same quality as the one that came originally with the vehicle. So preseving the original parts as much as one can is the way to go.

The O2s may cost $400 in all and one recovers that money over better MPG over 1 yr.

I must tell you also that Toyota does really make good products, no doubt about it.

No doubt but i am getting the same MPG as when new and if the o2 sensors were not functioning properly wouldn't the computer tell me? Most of my buddies and mine are high speed interstate driving. I don't recommended it by any means bur my buddy still has the original trany fluid in it. New fluid would probably scare it now.

Ethenol has caused a decline in mpg.. you are getting up 10% less gas in your tank... also the cats are under warranty for 8 yrs 80k miles if that helps