Bad mileage + 420 code + funky smell = bad cat?

[jfacker]

Hola USMB-ers,

 

Last year my 1998 Outback got a nice new CCR 2.2L engine to replace the 2.5L with blown head gaskets (gasp! yes, it's true).

 

The fuel efficiency started out OK but has gone badly downhill over the last year. I'm getting about 15MPG in town and 20 on the highway. Not good.

 

Plus, I've had a gas-like smell on startup (like gas, but not gas from the pump, maybe gas mixed with something else) you can smell inside and outside the car for a few minutes after starting the engine.

 

AND the car has thrown the CEL with the 420 code quite a few times now. I don't remember for sure, but I think it may have been throwing that code BEFORE the engine replacement.

 

Help! Is my cat clogged? The car idles unevenly and feels like it wants to take off at stop lights (putting the car in neutral helps). And the performance is awful, as in, mash the pedal, and nothing happens. It's hard to get the car to downshift if you need speed in a pinch.

 

A local mechanic suggests doing both O2 sensors before doing the cat, but I don't want to waste time if the cat's clogged anyway (would bad sensors explain the smell?)

 

Any thoughts you guys have would be GREATLY appreciated. For reference, this is a AT, not a manual, with about 180K miles total (only 8K on the new engine).

 

Thanks,

 

Jeff

[Snowman]

If the EJ25 puked a bunch of stuff into the cat, it probably did destroy it.

 

Take it to somebody with a scan tool that can view the oxygen sensor voltages (just about any real scan tool). With the car warmed up and in closed loop, the front sensor should fluctuate above and below .45v, and the rear should stay pretty steady near .45v. If the rear is fluctuating, you know that the sensor is good and the cat is not working. (of course, if you replace the cat, I would replace both sensors at the same time).

[jfacker]

Actually there were some CEL instances indicating misfires before the EJ25 was removed. So I guess it's possible it spewed out a bunch of junk into the cat. I drove the car for quite a while with the blown gaskets (and suspected this probably wasn't a good idea, but hey, I needed to get around). As long as it didn't approach the redline, it just produced bubbles through the coolant. If you pushed the engine too hard, though, it would blow out the coolant and overheat. Ah, those were the days. At least I was getting better gas mileage.

[suberdave]

smell and bad performance... i would bet on a bad cat...

 

-=Suberdave=-

www.suberdave.com

[lyonlyon]

Hola USMB-ers,

 

Last year my 1998 Outback got a nice new CCR 2.2L engine to replace the 2.5L with blown head gaskets (gasp! yes, it's true).

 

The fuel efficiency started out OK but has gone badly downhill over the last year. I'm getting about 15MPG in town and 20 on the highway. Not good.

 

Plus, I've had a gas-like smell on startup (like gas, but not gas from the pump, maybe gas mixed with something else) you can smell inside and outside the car for a few minutes after starting the engine.

 

AND the car has thrown the CEL with the 420 code quite a few times now. I don't remember for sure, but I think it may have been throwing that code BEFORE the engine replacement.

 

Help! Is my cat clogged? The car idles unevenly and feels like it wants to take off at stop lights (putting the car in neutral helps). And the performance is awful, as in, mash the pedal, and nothing happens. It's hard to get the car to downshift if you need speed in a pinch.

 

A local mechanic suggests doing both O2 sensors before doing the cat, but I don't want to waste time if the cat's clogged anyway (would bad sensors explain the smell?)

 

Any thoughts you guys have would be GREATLY appreciated. For reference, this is a AT, not a manual, with about 180K miles total (only 8K on the new engine).

 

Thanks,

 

Jeff

 

Dude 420 code!? easy peasy, your car is smoking ganga!! J

[zyewdall]

Someone should move this to the new gen forum -- might get more good answers there. My first thought on seeing the post was that the problem with your car is that it's too new -- none of ours give more than a two digit error code at most