Can running a car without the Muffler cause the O2 Sensor to set the CEL? 1997 Legacy GT.

 

This is the car a traded an ATV for. After several restarts I only get one code and that is the O2 Sensor.

 

Thanks for any help.

I doubt the lack of a muffler will cause the O2 sensor reading.

 

Is it the front or rear O2 sensor?

 

Put the system back to normal and see what the codes are. If you have a good scanner or meter you can watch the O2 sensors.

What actual code is it coughing up?

I doubt the lack of a muffler will cause the O2 sensor reading.

 

Is it the front or rear O2 sensor?

 

Put the system back to normal and see what the codes are. If you have a good scanner or meter you can watch the O2 sensors.

I am pretty sure it is the rear sensor.

 

Is it possible for the average Joe to put in a muffler? It looks like there is the muffler and possibly a small piece of tail pipe missing off the end of the pipe.

 

No offense to any Joe's.

There are 4 sections to the typical Subaru Exhaust that are bolted together, so yes anyone should be able to hook them up.

 

Y-pipe engine to CAT

Cat Pipe, front and rear CAT and the O2 sensors

Mid-pipe - Cat to Muffler has a resisnator in it.

Muffler

 

The Muffler you can get from the yards. Most of the other are trash as the yards cut out the cats. They cut the Y-pipe and Mid Pipe to get out the cats.

 

I have most of these if you need them. I'm in Colorado.

There are 4 sections to the typical Subaru Exhaust that are bolted together, so yes anyone should be able to hook them up.

 

Y-pipe engine to CAT

Cat Pipe, front and rear CAT and the O2 sensors

Mid-pipe - Cat to Muffler has a resisnator in it.

Muffler

 

The Muffler you can get from the yards. Most of the other are trash as the yards cut out the cats. They cut the Y-pipe and Mid Pipe to get out the cats.

 

I have most of these if you need them. I'm in Colorado.

 

Thanks for the info. I saw on Ebay a muffler with some pipe that is 56" long. It looks like it bolts onto the center where the second cat is. Let me look at it again tomorrow and see just what all I need. Colorado Springs is 5 hours from me. I made a few trips down there a few years back. That muffler on ebay is this one.

http://www.ebay.com/itm/Natural-New-Muffler-56-Round-Sedan-Subaru-Legacy-99-98-97-96-95-Parts-Car-Auto-/230716931120?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1997|Make%3ASubaru|Model%3ALegacy|Submodel%3AGT&vxp=mtr&hash=item35b7ccfc30

Some folks who have battled the dreaded P0420 code (converter efficiency) have found that an exhaust leak downstream of the second O2 sensor can indeed trigger that particular code.

 

So, it may be an improbable, but it is possible the lack of a muffler could cause a code.

 

 

Dave

How could an exhaust leak downstream of the second O2 sensor set off a 420?

Edited January 6, 201214 yr by J A Blazer
typo

It doesn't necc need to be a big change in anything, the sensor is very sensitive, it runs on the ragged edge of alarming all the time.