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Originally posted by colin14

have clogged front catalytic converta is there a way to run car without the front cat.car is 91 liberty\legacey fwd auto need help

is there a alternative.colin14............

 

I did an emergency repair to an older one piece Y pipe/cat that involved cutting the rear outlet pipe, punching out the catalyst material and then reconnecting the rear outlet pipe with a clamp. It allowed the car to run while I awaited a replacement, but it did not run well. In addition to not running well, running without a catalytic convertor is illegal.

 

All of the alternatives that I know of are from North American suppliers and are generally not good quality products. MRT in Australia has some good aftermarket performance exhausts and cats and the cost is likely less than a new Subaru part, but it may not be what you are looking for. I would check with a non-dealer Subaru mechanic in your area, if a local aftermarket part exists he should know about it.

 

Your best route is most likely to secure one from a scrapyard.

 

Even though your cat was old and near or past the end of its normal service life (13 yrs is old), you should determine if any of the following problems contributed to the cat failure:

 

* burning oil (oil will not completely burn until the cat burns it, and this clogs the cat) (how is your oil level)

* rich air/fuel mixture (like oil, the cat will burn the unburnt gas and cause the cat to overheat and plug)

 

Along with the cat I would change the oxygen sensor unless it is new. A correctly functioning oxygen sensor should keep the A/F ratio within range and protect the cat and keep emmisions low.

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alias2035 thank's for that info will checkout MRT. the price of cats

here in aus is ridiculas they want a arm and leg.luckily the car does not burn or use oil it just has no aceleration going up steep

hills no power but doesn't stall.colin14

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Originally posted by colin14

alias2035 thank's for that info will checkout MRT. the price of cats

here in aus is ridiculas they want a arm and leg.luckily the car does not burn or use oil it just has no aceleration going up steep

hills no power but doesn't stall.colin14

 

When cats plug the car will usually not run at all, or run very very badly, hardly able to idle. Your cat will also glow in the dark because it will get very, very hot!!

 

Are you sure your cat is the the problem? The Legacy cats are not known for too many problems, as the Legacy fuel injection system prevents the rich a/f ratio problems that caused issues on the older EA81/2 Subaru's.

 

I would check the intake side for signs of trouble with the A/F ratio such as the MAF sensor and TPS sensor (not detecting FOT?), and possibly the pre cat oxygen sensor (the one and only oxy sensor on your car?).

 

Some shops can install a backpressure guage in place of the oxygen sensor to detect excessive backpressure which is usually indicative of a clogged catalytic converter. Unfortunately most shops would rather change parts than diagnose. With this test the oxygen sensor will be disconnected, and the ECU will net to be reset afterwords.

 

Speaking of reseting the ECU, I would unplug the negative battery terminal for 15 minutes to restore the factory settings. When the battery is reconnected the ECU will relearn the sensor paramters during the first drive. Sometimes this cures problems, but not all that often, but it is worth a shot since it is a no cost item.

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