Pontiac6KSTEAWD Posted August 25, 2009 Share Posted August 25, 2009 Ok guys, Working on my 01 Legacy Outback, with 190k miles. Some details.. Subaru issue Had car inspected. NOx reading was 14.2, limits is 15.0 Even though it passed, was advised to have it looked at. Recommendations are either 1) replace or clean EGR Valve or 2) replace Cat. pipe w/ both O2 sensors 2001 Subaru Legacy Outback 2.5ltr manual transmission Following have been replaced in the last 3 weeks. Engine (used w/ 52k mileage), Plugs and Wire-set, All belts (timing belt, drive belts), Differential fluid, M/T Fluid, Antifreeze, Oil Change, Fuel/Air filter, fuel injectors (30k ago), driveshaft/camshaft seals, clutch, and lots of other stuff. Suggestion about how to correct the NOX. We did have a check engine light after the new engine was put in. We reset it, and it hasnt come back. So not lights on the dash.. Quote Link to comment Share on other sites More sharing options...
OB99W Posted August 26, 2009 Share Posted August 26, 2009 (edited) As with many problems, there are a few possible causes of excessive NOx. If we assume that the cat is okay, then it pretty much leaves things that cause the combustion temperature to be too high. Generally, that would suggest either the mixture is too lean, or the EGR isn't feeding enough exhaust back to the intake. If you can post other emissions numbers (CO, HC, CO2, O2), I can give a better idea of what to concentrate on. Otherwise, you could start with checking for intake vacuum leaks and/or cleaning the EGR valve and passages and see if that helps. Edited August 26, 2009 by OB99W Quote Link to comment Share on other sites More sharing options...
idosubaru Posted August 26, 2009 Share Posted August 26, 2009 given the completeness of the tune up you've done i'd install a new Subaru PCV valve while you're at it. it's not a likely culprit of your problem but good time to replace it with everything else and only costs a few dollars and is easy to replace. was this before or after the engine replacement? how soon after engine replacement was the test done? Quote Link to comment Share on other sites More sharing options...
Pontiac6KSTEAWD Posted August 26, 2009 Author Share Posted August 26, 2009 3 weeks laterm, after the engine install, the test was done, Colorado Emissions crap... Already did the PCV valve at engine install... Sheet reading numbers from the inspection.. HC Reading 0.531 Limit 1.2 CO Reading 6.6509 Limit 15.0 CO2 Reading 402.2405 Limit NA NOX Reading 1.4174 Limit 1.5 Took a closer look at the engine. According to Subaru dealer the old engine had a EGR valve, the new engine does not. The engine came out of 01 Outback AWP (VIN verified), however the new engine was a automatic, and the car its in is a 5 speed. So not sure if this has anything to do with it. There was also a diference in the Crankshaft timing belt cog. But we swapped that over, and no problems as of yet. The odd part is that I cant even find the wiring harness for the EGR valve, and neither can the dealer.. Quote Link to comment Share on other sites More sharing options...
OB99W Posted August 27, 2009 Share Posted August 27, 2009 Took a closer look at the engine. According to Subaru dealer the old engine had a EGR valve, the new engine does not. The engine came out of 01 Outback AWP (VIN verified), however the new engine was a automatic, and the car its in is a 5 speed. So not sure if this has anything to do with it. There was also a diference in the Crankshaft timing belt cog. But we swapped that over, and no problems as of yet. To determine if the original engine had an EGR valve, look at the emissions label pasted on the underside of the hood. The odd part is that I cant even find the wiring harness for the EGR valve, and neither can the dealer.. What wiring? Since the emissions numbers other than NOx are ''in the ballpark'', it's unlikely that the cat isn't functioning well enough. Anything you can do to cool combustion temps will lower NOx. As I said previously, be sure there are no intake vacuum leaks that might lean the mixture. Make sure the cooling system is up to par. Don't use more than 50% ethylene glycol in your coolant, since water does a better job when it comes to getting rid of heat. Even an OEM Subaru thermostat versus an aftermarket one can make a difference when things are that close. Why was the original engine replaced? (That might give us a clue as to what's going on now.) Quote Link to comment Share on other sites More sharing options...
Pontiac6KSTEAWD Posted August 27, 2009 Author Share Posted August 27, 2009 2 Cylinders lost compression. Unknown as to why, we really didnt dig into far cause the new engine had 52k, and was 300 bucks. There isnt any wiring for the EGR system? First time I have ever seen that. The picture the website has shows a 2 wire plug, but it could be a generic picture.. We looked at the emissions label under the hood. It makes no mention of a EGR valve, in writing, or in the pic. I still have the old engine in storage (its for sale if anyone wants it), I will have to go down there and take a look at her. If there is a diference inbetween the two engines, then what? Quote Link to comment Share on other sites More sharing options...
Pontiac6KSTEAWD Posted August 27, 2009 Author Share Posted August 27, 2009 A little more investigation.. According to everything that I have found, a 01 Legacy Outback does NOT have a EGR valve. Only the Forester and the Impreza for that model year had one. This new engine came off a 01 Legacy Outback AWP (all weather package). We swapped the intake from the old engine, and put it on the new engine, which is where the EGR would be located, if it had one. Which it doesnt. So I think this car does NOT have a EGR valve to begin with. Quote Link to comment Share on other sites More sharing options...
OB99W Posted August 27, 2009 Share Posted August 27, 2009 (edited) There isnt any wiring for the EGR system? First time I have ever seen that. The picture the website has shows a 2 wire plug, but it could be a generic picture.. We looked at the emissions label under the hood. It makes no mention of a EGR valve, in writing, or in the pic.[...] According to everything that I have found, a 01 Legacy Outback does NOT have a EGR valve.[...] The ECU would have tested for EGR operation if there was one on the original engine, and noticed if it was missing -- since you didn't report a CEL and code, I suspected there was no EGR on your original engine. Subaru has used EGR off and on in various configurations, and I admit that I haven't memorized each of them. Earlier models (my own 1999 Legacy Outback for example) had strictly vacuum-operated EGR, with no electrical connection. I'd like to reconsider the emissions numbers. Even though the HC and CO are well within the limits you posted, they may still be high. Could you provide the units (ppm, %, etc.) for the HC, CO, etc.? EDIT: Usually AWD vehicles are exempt from chassis dynamometer testing, but if they run a 4-wheel dyno the test could be an IM-240. If so, the emissions might be in grams/mile. Is that the case? Edited August 27, 2009 by OB99W Questioning possible IM-240 test Quote Link to comment Share on other sites More sharing options...
OB99W Posted August 27, 2009 Share Posted August 27, 2009 I'm going to assume that the emissions numbers posted were for an IM-240 test. NY doesn't require IM-240, so I wasn't that familiar with typical results. I looked into it, and it appears the Colorado limits are very generous -- even if the car passed, the emissions are high. It seems that if the engine is properly warmed and running closed-loop, more-typical results would be about: HC 0.1 gms/mile CO 1.5 gms/mile NOx 0.6 gms/mile Those are quite a bit lower than the readings posted. It seems that the first thing to do is verify that the ECU is going closed-loop -- if not, high emissions are expected. If it's staying open-loop, it might be that the coolant temperature sensor is defective. If the ECU is going closed-loop, then verify that the front A/F (O2) sensor is working correctly. As long as that's okay, the probability is that the catalyst isn't up to the job. Since the original motor had two bad cylinders, it might have dumped raw fuel into the cat and damaged it. Quote Link to comment Share on other sites More sharing options...
LynxCub Posted September 11, 2009 Share Posted September 11, 2009 Hello All, I'm actually the guy with all the issues listed. My brother was helping me out. Today I replaced the Cat. Pipe and replaced both front and rear O2. The cat pipe is a Federal vs California. Reset the engine errors codes, and will drive it. Hopefully I won't see another check engine code. Can't Remember the error code, but per AutoZone, the readings indicated: 1) A/F 2) Cat. If this fails, how do I go about checking the ECU for open/close? Thanks for all your help!! :-\ Quote Link to comment Share on other sites More sharing options...
Pontiac6KSTEAWD Posted September 13, 2009 Author Share Posted September 13, 2009 As I said over the phone bro, got to wait until the new cat and O2 sensor gets warmed up, and fully programmed into the computer, to see if another check engine code comes up. Would also be curious to see if your fuel milage picks up after the O2 sensor replacement,. Quote Link to comment Share on other sites More sharing options...
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