[96 Legacy LSI 2.5 Automatic p0420 no CEL]

I think you're probably right about the front ox censor. I have 130 k and have never done it. I'll let you know if it works.

Thanks

[96 Legacy LSI 2.5 Automatic p0420 no CEL]

I've been trying to figure this one out for days searching the car and forums. It runs perfect except when in drive at idle(at a stop light, drive thru, etc). The idle drops after about 8 seconds of sitting. It feels like it will die but never does. It just goes up and down. It sounds like it's being choked. I've done a full tune(OEM plugs, wires, fuel and air filter, checked all vaccum lines, etc) The CEL doesn't come on but it will pull the code p0420(Catalyst system efficiency below threshold) when its doing the funny idle. I saw that one guy wrote that the P0420 means it's time for a break. I believe it. This keeps me up at night just trying to think through it. I've seen similar posts from years past but have never seen anyone come to a conclusion and solve the problem. I've found no solutions. Please Help.

[Misfiring Outback]

Make sure you're plugs are NGK OEM. I put Bosch in mine and it did the same thing your's is doing. I put the OEM plugs in and it runs like a top. Try the obvious easy cheap fix before going on. Also make sure you're running premium gas. It makes a huge difference in the 2.5 litre.

[96 LSI Hesitation and then Clunk]

Check to be sure all electrical plug in connections are good under the hood, also vacuum hoses. Air cleaned might be worth checking too.

 

I had an interrmittend hesitation over the last two weeks. I removed the MAF on Sat. and "Carefully" cleaned it. I used a spray cleaner, (gumout should work) but DID NOT TOUCH. I figured if it was shot it was worth a try. I have not had the problem since.

 

Good luck

I found out the clunk was actually a small back fire. I finally got the engine light to flash. I checked pressure and determined it was a misfire. When I replaced the spark plugs a few months ago I used Bosch Plat. From reading forums I learned that was a no no. I just switched everything to NGK plugs and the whole problem is fixed!! How weird is that. So there is a reason that NGK plugs are OEM for Subarus. The thing went from barely running to feeling like a race car. Thanks for all the advice.

[96 LSI Hesitation and then Clunk]

I've read all the posts reguarding hesitation and can't find anyone that has this problem. When I baby or feather the car (warm or cold) it runs fine. When I need to go up a little hill or really step on it the car hesitates badly and lately has been making a clunk or knock sound right in the middle up front right as it starts hesitating. The Service Engine Soon light isn't coming on. I have new plugs and wires, fuel filter, air filter, tranny serviced by subaru 2 months ago. I always run premium gas. I don't know what else to do. Anyone had this problem?

Also I just changed the right front cv axle a couple weeks ago. It's a different clunk or knock sound than that makes.

[canine vs. carpet HELP!]

Get some Floormats she'll never notice!

[96 LSI Hesitation and then Clunk]

I've read all the posts reguarding hesitation and can't find anyone that has this problem. When I baby or feather the car (warm or cold) it runs fine. When I need to go up a little hill or really step on it the car hesitates badly and lately has been making a clunk or knock sound right in the middle up front right as it starts hesitating. The Service Engine Soon light isn't coming on. I have new plugs and wires, fuel filter, air filter, tranny serviced by subaru 2 months ago. I always run premium gas. I don't know what else to do. Anyone had this problem?