JIMMYRIG Posted April 16 Share Posted April 16 Just failed smog in my 89 4.0 Hoping its not the cat but my NO numbers were way high. Guy said it could've been EGR too but idk if it would cause this big of a spike. I attached the results from the test below... Any recommendations as to what I should do? Link to comment Share on other sites More sharing options...
Salvagedcircuit Posted April 16 Share Posted April 16 It looks like you linked to an email in your inbox. Try taking a photo / screenshot of the report you got so we can try to help you. Thanks! Link to comment Share on other sites More sharing options...
JIMMYRIG Posted April 16 Author Share Posted April 16 Let me know if this works Link to comment Share on other sites More sharing options...
Ωhm Posted April 16 Share Posted April 16 Your results show your running LEAN. Link to comment Share on other sites More sharing options...
JIMMYRIG Posted April 16 Author Share Posted April 16 I know the o2 is a little high but thats not related to NO right Link to comment Share on other sites More sharing options...
Ωhm Posted April 17 Share Posted April 17 Both are related through combustion. As O2 climbs, so does NOx. Link to comment Share on other sites More sharing options...
JIMMYRIG Posted April 17 Author Share Posted April 17 Could it just be an o2 sensor causing the ecu to tune lean? Link to comment Share on other sites More sharing options...
Ωhm Posted April 17 Share Posted April 17 It's hard to say without knowing if you're in Closed or Open Loop. Link to comment Share on other sites More sharing options...
fiatslug87 Posted April 17 Share Posted April 17 Do you have a Renix Engine Monitor? If not check the resistance between A & B of the O2 sensor reading should be 5-7Ω. You can also check EGR function? https://comancheclub.com/topic/73480-21-–-renix-egr-valve-test/#comment-769327 From the FSM is in this post. https://comancheclub.com/topic/38225-egr-solenoid-renix/ Link to comment Share on other sites More sharing options...
pizzaman09 Posted April 17 Share Posted April 17 As you are running lean, it's worth checking to see if your manifold bolts are tight at the head. Checking for any vacuum leaks before trying to chase emissions stuff is a good place to start. Link to comment Share on other sites More sharing options...
JIMMYRIG Posted April 17 Author Share Posted April 17 If it were EGR would a symptom be high idle at startup? 1 in 10 times I start up it revs to ~3k rpm. I don't have a renix monitor. I'm not familiar either Ill check the o2 aswell Link to comment Share on other sites More sharing options...
JIMMYRIG Posted April 17 Author Share Posted April 17 Just now, pizzaman09 said: As you are running lean, it's worth checking to see if your manifold bolts are tight at the head. Checking for any vacuum leaks before trying to chase emissions stuff is a good place to start. I checked vacuum leaks yesterday by spraying brake clean around all hoses and connections to try to get it to rev up. Nothing Link to comment Share on other sites More sharing options...
89 MJ Posted April 17 Share Posted April 17 It’s common for the bolts holding the intake manifold to the head to loosen up. Be sure to check on the underside too. Link to comment Share on other sites More sharing options...
JIMMYRIG Posted April 17 Author Share Posted April 17 Will do Link to comment Share on other sites More sharing options...
JIMMYRIG Posted April 18 Author Share Posted April 18 So I'm not getting vacuum signal to the transducer or the EGR. I'm getting vacuum to the inlet on the solenoid. I'm gonna check the connection to the solenoid with a multimeter but I'm thinking its the solenoid. Likely causing the high revs at startup and after freeway driving and also running lean. But tell me if I'm missing something 18 hours ago, fiatslug87 said: Do you have a Renix Engine Monitor? If not check the resistance between A & B of the O2 sensor reading should be 5-7Ω. You can also check EGR function? https://comancheclub.com/topic/73480-21-–-renix-egr-valve-test/#comment-769327 From the FSM is in this post. https://comancheclub.com/topic/38225-egr-solenoid-renix/ Link to comment Share on other sites More sharing options...
Ωhm Posted April 18 Share Posted April 18 33 minutes ago, JIMMYRIG said: So I'm not getting vacuum signal to the transducer or the EGR. I'm getting vacuum to the inlet on the solenoid. EGR Solenoid needs to be de-energized, with engine RUNNING, so vacuum can flow to Transducer or the EGR valve. Disconnect EGR Solenoid electrical connector, then test. Link to comment Share on other sites More sharing options...
JIMMYRIG Posted April 18 Author Share Posted April 18 5 hours ago, Ωhm said: EGR Solenoid needs to be de-energized, with engine RUNNING, so vacuum can flow to Transducer or the EGR valve. Disconnect EGR Solenoid electrical connector, then test. I thought it stops letting vacuum through when it’s de-energized. Link to comment Share on other sites More sharing options...
rokinn Posted April 18 Share Posted April 18 I had a high Nox situation with my last emissions test which failed. REM says my vac is about 3/5ths of what it should be. Tested all of the lines with vac tester - all good. Knew the manifold bolts were good because I tightened them when I had the head milled. Again when I replaced the clutch and slave swap. Finally replaced the front tube on the valve cover with new. Viola - VAC up to 15 - 16 inHG. Passed emissions with flying colors. Link to comment Share on other sites More sharing options...
JIMMYRIG Posted 13 hours ago Author Share Posted 13 hours ago So my egr doesnt seem to be the issue with high idles at startup and after highway driving. I think its something to do with the tps or map. But as the EGR still isnt functioning should I entertain fixing it or just replace the cat? Rock auto has a new cat for less than $200. My thought is the egr couldn't cause that big of a spike in Nitric. Any thoughts? Link to comment Share on other sites More sharing options...
pizzaman09 Posted 13 hours ago Share Posted 13 hours ago 1 minute ago, JIMMYRIG said: So my egr doesnt seem to be the issue with high idles at startup and after highway driving. I think its something to do with the tps or map. But as the EGR still isnt functioning should I entertain fixing it or just replace the cat? Rock auto has a new cat for less than $200. My thought is the egr couldn't cause that big of a spike in Nitric. Any thoughts? If your going to buy a cat, buy one from Magnaflow directly, super high quality and they gave me $75 for my core with prepaid shipping back. It was actually less expensive than most of the Rock Auto cats before the core refund. Link to comment Share on other sites More sharing options...
JIMMYRIG Posted 12 hours ago Author Share Posted 12 hours ago I live in CA. The Ca compliant direct fit magnaflows are $1000+ Link to comment Share on other sites More sharing options...
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