Exhaust Donut

[irbryanxp]

Does anyone know how to replace the notoriously failing exhaust donunut on a 1998 corolla? I want to replace it myself. Is it a difficult task?

[fishexpo101]

Which one - there are two that are likely to fail - the one between the catalytic converter and the front pipe (cylindrical donut), and the one between the front pipe and the exhaust manifold (conical donut)?

About the same amount of work for both - not really hard, just lots of screwing around to get to the gaskets themselves.

For the one between the exhaust manifold and the front pipe - the O2 sensor is in the way of the spring bolts. Will have to pull that sensor off, which means you'll likely have to remove a lower heat shield bracket - where the bolts are in a funky angle.

For the one between the front pipe and catalytic converter - you'll have to be able to slide the catalytic converter assembly far back enough to allow you to slip in a new gasket. Tightening that back together, especially with an aftermarket strap bracket will be tough.

First time I did it - did it myself - took the better part of the day, just to get the fasteners off of interfering brackets before I could get at the springs bolts and fighting the exhaust hangers to allow me enough slack to separate the piping. This last time I needed to have it done - took it to a shop and they replaced both for $50 in labor - I provided the gaskets.

[irbryanxp]

Originally Posted by fishexpo101

Which one - there are two that are likely to fail - the one between the catalytic converter and the front pipe (cylindrical donut), and the one between the front pipe and the exhaust manifold (conical donut)?

About the same amount of work for both - not really hard, just lots of screwing around to get to the gaskets themselves.

For the one between the exhaust manifold and the front pipe - the O2 sensor is in the way of the spring bolts. Will have to pull that sensor off, which means you'll likely have to remove a lower heat shield bracket - where the bolts are in a funky angle.

For the one between the front pipe and catalytic converter - you'll have to be able to slide the catalytic converter assembly far back enough to allow you to slip in a new gasket. Tightening that back together, especially with an aftermarket strap bracket will be tough.

First time I did it - did it myself - took the better part of the day, just to get the fasteners off of interfering brackets before I could get at the springs bolts and fighting the exhaust hangers to allow me enough slack to separate the piping. This last time I needed to have it done - took it to a shop and they replaced both for $50 in labor - I provided the gaskets.

Well I had my flexpipe replaced so would that have taken care of either of the two gaskets? I hear what sounds like an exhaust leak when I'm accelerating and when I give more gas under certain conditions. On my car it sounds like its coming from up-top on the motor.

[leakyseals]

Originally Posted by irbryanxp

Well I had my flexpipe replaced so would that have taken care of either of the two gaskets? I hear what sounds like an exhaust leak when I'm accelerating and when I give more gas under certain conditions. On my car it sounds like its coming from up-top on the motor.

That should have fixed it, how long ago? also, as the word says it flexes. Before it gets too hot you can muscle it a bit, sometimes it's all thats needed.

[irbryanxp]

I had it replaced about 6 months ago and the noise was there before and after the flexpipe replacement. Could it be a manifold leak?

[leakyseals]

Originally Posted by irbryanxp

I had it replaced about 6 months ago and the noise was there before and after the flexpipe replacement. Could it be a manifold leak?

Could be, but usually its the gaskets between the exhaust manifold and the pipe, or the pipe and the cat. If the mechanic didn't replace the gaskets, just the pipe who knows. But I would replace the gaskets first, as they are known to burn up over about 50k

[irbryanxp]

I know the gaskets were replaced because theres a charge for 2 gaskets on the receipt. Today the muffler hanger broke it's one thing after another with this car....