matt167 Posted October 11, 2015 Share Posted October 11, 2015 My 2001 Forester is a CARB car. I decided to look up Cats in case it ever needed one and only a couple say CARB compliant but they all look the same. There is at least $100 difference between non CARB Vs CARB.. If I put a Federal CAT pipe on my car, will it throw a CEL? Inspection only checks for CEL when it's scanned Quote Link to comment Share on other sites More sharing options...
Bushwick Posted October 11, 2015 Share Posted October 11, 2015 (edited) You need to find out the style of cat they installed and match the style, whether OEM new or aftermarket new. Aftermarket new will be MUCH cheaper as they use less precious metals in them vs. OEM. I forget the names of the different cats off hand, but if you go to say Summit Racing and type in Subaru, it should ball-park it and name the type. I went with a Magnaflow universal in my 99' Saab from Summit Racing and it was around $100. It passed e-check w/o issue last time. And yes, you need a CARB approved one if that's what NY's draconian laws state. Edited October 11, 2015 by Bushwick Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 12, 2015 Author Share Posted October 12, 2015 (edited) I got a feeling the carb compliance is a certification only.. If the light is out it will pass inspection, so as long as they are good enough, they should work.. IF they are good enough. Edited October 12, 2015 by matt167 Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted October 12, 2015 Share Posted October 12, 2015 From what I understand the carb cats are supposed to operate at a higher temperature than non-carb. Because of the way the feedback system works on the carb models, a non-carb cat may not actually reach proper operating temp, which will reduce its efficiency, and will probably set a P0420 code. Going the other way, carb cat on a non-carb car, may cause the cat to run too hot and cause it to melt down. Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 12, 2015 Author Share Posted October 12, 2015 I see, that kinda makes sense.. Cats look fairly new on this. I haven't checked closely but they might even be OEM replacements. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted October 12, 2015 Share Posted October 12, 2015 I'd be concerned WHY they are getting replaced and having issues. If the engine is running correctly, they should last a LONG time so be fix whatever is causing failure. I'm going to reiterate, make sure the replacement is the same "style" as OEM. Also, NY does visual inspections, correct? If whatever is supposed to be on the cat isn't, they could fail your inspection. Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 12, 2015 Author Share Posted October 12, 2015 there not getting replaced. I was pricing them. Their supposed to but only do that to 1995 and older. No shop around here would pass it with the wrong cats if cel was off with no codes Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 15, 2015 Author Share Posted October 15, 2015 I'll add a little bit to this.. A day after I bought this car. The CEL came on, so I know the PO reset the codes. I didn't have a code reader since my OBD-SX vanished one day a year or so ago.. Working nights, I did not get codes scanned at Advance till a couple days ago but had a suspect that it was P0447 or P0420. It came back as P0420. I had read that Subaru would not replace a cat under 80k miles UNLESS it had a decarbonizing treatment done. Since I work at Walmart TLE and we do that, I dropped $20 on the service and the light went out for a brief time, about 30 miles.. So the test to me, proved either working sensors or the Cat was working correctly for a brief time, or the sensors fouled up from the decarbonizing and turned the light off when the downstream readings normalized due to the oil in the decarbonizer covering the O2 sensor... I have a new OBD-SX coming in the mail for tomorrow, and a new downstream O2 sensor. I think I'm going to install the sensor in a spark plug anti fouler, reset the code, run it around and the light should stay off Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted October 16, 2015 Share Posted October 16, 2015 There's a whole gigantic list of things that can set a p0420 code. Everything from a vacuum leak, to an exhaust leak, to a dirty air filter, or poor ground connections. First things first. Make sure the basics are in good shape. Plugs, wires, filters, Subaru PCV valve. Check all the vacuum and breather hoses for proper connection. After that go after O2 sensors. Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 16, 2015 Author Share Posted October 16, 2015 vac and breathers are good. I didn't check the PCV but I do have a spare used one from a 1999 EJ25D if they are the same valve.. It probably could use plugs and wires since they are unknown, but this engine does not run bad at all.. Exhaust is probably OEM, in good shape. no leaks in that. It's probably the cleanest, quietest Subaru with this kind of miles that I've been in, it has to be all highway miles cause any salt roads and this thing woulda been gone long ago. Once I get the OBD-SX I can make sense of the live data and figure it out.. Not having that is why the light is still on, but I never kept track of my last one after it was lent out last ( I was moving ) and now they say they gave it back to me.. The only thing I about guarantee is that the decarbonizer turned the light off since it was only after the treatment that it went out after a 50 mile ride home last night, light went out when I warmed it up this morning before leaving.. .. It's another $20 to prove that tho... I've been driving it daily for a week with the light on otherwise this is the stuff we use at Walmart minus the TB cleaner. comes in shrink wrapped together. http://www.autoparts2020.com/rsdev/part_detail.jsp?PART_HDR_ID=84220 Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 17, 2015 Author Share Posted October 17, 2015 III put my new scanner on it. Front is switching, rear lambda sensor is switching also. Its slower but switching and the voltages are similar.. All emssions readyness tests except catalyst had passed... The freeze frame showed the sensors identical voltage, 36 mph and like 14% load Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 19, 2015 Author Share Posted October 19, 2015 Well, this turned into an ordeal but it's fixed... I studied the PID readings on the scanner during a drive, and the rear o2 was definitely mimicking the front at a slightly higher voltage. Coupled with the fact that the cats I found are cheap aftermarkets and not Subaru OEM, they probably were/are not functioning well, but not 'clogged'.. Coupled with that and the fact the only thing that inspection cares about is the CEL and the cats being there. I decided to go forward with the anti fouler.. Well, someone never put any anti seize on the sensor, and the cheapie Cat only had the sensor bung brazed in place and not well at that, it actually freed itself from the cat body with very little force... So I decided to weld it back in place. I threaded the anti fouler in the bung before welding, and actually welded both into the cat.. I did it on the car with 7014 rod and an old lincoln A/C 225 tombstone. I didn't think it would work but somehow, got it all sealed up and it seems to be fine.. Welds aren't pretty but solid enough.. No lights yet but the ride to work tomorrow will tell Quote Link to comment Share on other sites More sharing options...
Bushwick Posted October 20, 2015 Share Posted October 20, 2015 I've used anti-foulers (stacked 2 of them, not one; one drilled out completely) on my Saab in the past and that kept the T5 system from popping a rear O2 code when the car was cat-less. IF your cat actually runs into an issue, the ECM will never know, so keep that in mind, and if you are running an incorrect cat it'll likely fail at some point, so get in the habit of pulling over and checking if the cat case is turning cherry red as that's extremely dangerous. The anti-fouler setup was designed more for cat-less cars with rear O2's vs. bypassing an unknown issue(s). I'd give the car a requisite amount of actual drive cycles and be wary if it actually stays off, as that'll indicate the cat was an issue. Not sure how Subaru does their 1st start ECM deal i.e. if the engine goes into a diagnostic type setting after hooking up the battery and 1st running, where it runs a battery of tests while it "learns", possibly staying in a closed-loop or something, then after X amount of actual start/running cycles, will release the codes it discovered. I know my Saab does this which can be annoying as it takes time to reappear. Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 20, 2015 Author Share Posted October 20, 2015 yea, its already cleared readiness test. I didn't mention before, i also used my IR thermometer and in and out were same temp.. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted October 21, 2015 Share Posted October 21, 2015 yea, its already cleared readiness test. I didn't mention before, i also used my IR thermometer and in and out were same temp.. How did you test the inner temp? You should still visually check periodically if it's glowing. It'll be more evident at night if it occurs. w/o the rear O2 detecting anything, you'll never know. Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 21, 2015 Author Share Posted October 21, 2015 spec for functioning cats is 500* hotter on the output vs the input. That is from the catalytic reaction. I used a laser non contact thermometer. The temp in and out is the same.. I was able to see honey comb when the bung was out of place, and its not clogged at least yet. Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 22, 2015 Author Share Posted October 22, 2015 well, passed inspection today.. Has a pending code for p0442, small evap leak. But my scanner said emissions test ready so I took it to the local small ford dealer, who's a good friend of mine... I think gas cap might have been loose, but I got a year to figure it out, if it does fail again and trigger CEL Quote Link to comment Share on other sites More sharing options...
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