Ravz Posted June 2, 2004 Share Posted June 2, 2004 Hey guys, I dunno how many of you have mandatory vehicle emissions testing in your region, but we have it here in BC, Canada - and my Pathy keeps failing!! It's ridiculous... There's 3 parts to the test: CO2 emmision, NOX and Hydrocarbons I think.... I've passed 2 out of the 3 items everytime but it keeps failing on the NOX part. It failed by 0.3 today - totally ticked me off. Quick run down: I got a brand new cat, O2, air filter is clean, NGK platinum plugs, the truck idle's and runs absolutley perfect. EGR valve has been cleaned out, cap and rotor are a few months old as well as the fuel filter. I run it on 91 octane fuel. Truck had 274,000 kms. I have no idea what to look at anymore! :furious: Any ideas???????????????????????? Ravz :help: Link to comment Share on other sites More sharing options...
wheel366 Posted June 2, 2004 Share Posted June 2, 2004 Here in NJ, we have a trick. Chevron makes a product called Techron fuel system cleaner. I failed emissions and I went and got myself a bottle of that stuff and drove around for 20 minutes, went back and passed. Not sure if it will work in your case, but it's a cheap option to try. Link to comment Share on other sites More sharing options...
JeepRescueService14 Posted June 2, 2004 Share Posted June 2, 2004 give the smog guy 100 bucks.. my pathy passed smog for $ 125 leaky exhaust, no cat and all !!! HAHAHA!!! Link to comment Share on other sites More sharing options...
88pathoffroad Posted June 2, 2004 Share Posted June 2, 2004 Quit running 91 octane in it. It's completely unnecessary and doesn't do anything for power or mileage. All it does is suck money out of your pocket. Using premuim gasoline only applies to cars that REQUIRE it. Your Pathy requires 87 octane fuel, was built to run on it, and runs best with it. Power gains, gas mileage and running smoother are all just myths. Look it up yourself if you don't believe me. One thing I've seen is that the EGR system likes to gum up with carbon and crap after a while. This means that the passage from the EGR valve itself through the lower intake manifold is almost completely or partially blocked and therefore not performing as needed to pass emissions. Cleaning out the valve itself will make that work properly, but if the intake passage is blocked it won't much matter, because it'll still be only allowing a small amount of recirc gas to be run through for idle emissions purposes...which is how your vehicle is tested... Another thing to check is the vaccuum system for cracked, loose or missing hoses. I'm no expert on emissions testing and how that works, but if any vaccuum lines are old and cracked (sucking partial vaccuum instead of full like they should be), it's going to run incorrectly, even if it is only by a few degrees or hydrocarbons or nitrous oxides. I'm not talking about big obvious cracks onm the outside of the hoses either, I'm talking about cracks that start at the ENDS of the hoses and go inside at the point of attachment. I've seen it happen on almost every car I've owned, and I think I'm up to about 15 by now... Link to comment Share on other sites More sharing options...
somethingcool Posted June 2, 2004 Share Posted June 2, 2004 Yeah, try it with 87 octane I bet you pass... Link to comment Share on other sites More sharing options...
Ravz Posted June 2, 2004 Author Share Posted June 2, 2004 Thanks for all the replies guys.... I only ran it on 91 octane for the emissions testing.. normally it gets 87. I have cleaned out the EGR valve BUT i couldn't remove the copper pipe that runs from the manifold to the EGR valve, it didn't budge no matter what I did. But I know it's not blocked because I did the manifold studs a few weeks back and had the whole works ripped apart, and i could blow air from one side to the other easily. Anyways, this weekend it's gonna get another look over and inspection by me b4 I try one more time for aircare. So you guys recommend 87 octane fuel?? Everyone up here swears by Chevron 94 octane for aircare, even for old cars..... Link to comment Share on other sites More sharing options...
88pathoffroad Posted June 3, 2004 Share Posted June 3, 2004 Premium burns slower than regular unleaded, which means you're passing more unburned fuel out the exhaust pipe by using it in an engine not built for it. It's not really a huge amount of unburned fuel, but I'm pretty sure it'd be better to just run 87 octane. Somebody correct me if I'm wrong... Link to comment Share on other sites More sharing options...
MatterHorn Posted June 3, 2004 Share Posted June 3, 2004 basically yeah ... but more or less it is changing the compressability of the fuel, so as it is squeezed, it is less likely to pre-ignite causing a ping ... since we dont have high compression, large bore motors, it's a complete waste to think that 91 or better octane fuel is needed ... if you are getting a ping, its because you need to adjust the timing and or have the injectors cleaned or replaced because of an excessively lean mixture ... at least with our motors ... Link to comment Share on other sites More sharing options...
John Boy Posted June 27, 2006 Share Posted June 27, 2006 Good thread and intresting. The previous owner which is a co worker of mine always ran 92 octane in it so I continued to do the same. I haven't put in 87 octane of fear it may start pinging. What you say about unburned fuel may be true because i do get a small smell of fuel around my truck and nothing is leaking. I'm almost at empty and going to give the 87 a try but I really hope it doesn't start pinging. Link to comment Share on other sites More sharing options...
Kn0xville Posted June 28, 2006 Share Posted June 28, 2006 if its only failing by that much. RETARD the timing. Thats how i got mine to pass. Link to comment Share on other sites More sharing options...
Indigent Posted June 28, 2006 Share Posted June 28, 2006 Put about 2 fl oz of acetone in a full tank. That seems to work here in Japan. My mechanic told me that he does it in every car that he takes to get inspected and never has problems. I know that mythbusters had a bit on acetone in fuel, but I am not talking about a full tank of acetone, just 2-3 fl oz per 10 gallons or so. ( I have a diesel, so I use less. I want cetane not octane.) Also if you look at msds sheets for the fuel cleaner additives, you will see acetone in roughly these percentages in their ingredients. more acetone than that is bad bad bad. just a thought Link to comment Share on other sites More sharing options...
thndrwhls Posted June 28, 2006 Share Posted June 28, 2006 I've got the same problem, I have an 89 pathy with TBI. The only time I passed inspection was when I first got my pathy. It wasent running well so I took it to a local shop, they tweaked it with a gas analyzer to where it passed, however it ran like @!*%. At the time I was pissed, they f'ed up my truck, had a friend that works for Nissan go through do a thorough tune up adjust the timeing, idle, etc... and it ran great, but has not passed inspection ever since. It fails the carbon Monoxide by like 1-2%, F'in re-****-u-lus... Anyway, now that the tags have been out for a year, I have had every code in the thing fixed, full tune up, new cat, O2, plugs wires, headers etc... I think I am going to try and pull the TBI, make sure the EGR passages are spotless, clean the MAF and see what happens. If that doesnt work then I am moving to where it doesnt matter. Freakin Smog Nazi's... Anyway, let me know if you come up with an idea that works. BTW 88, have you heard anything from L&P about a system they are developing to better fuel economy and emissions. I seem to remember Lee saying something about this months ago when I was discussing these problems with him. he was saying the proto was getting like 21 MPG, least I think thats what I remember... Peace Brutha's... Link to comment Share on other sites More sharing options...
thatguy03 Posted June 28, 2006 Share Posted June 28, 2006 yah man i feel ur pain i hate aircare i just took mine through last week thank god it passed anyways my little tricks i learned over the years is go to mowhawk get the ethanol blend gas and taker her for a good hard boot get that cat heated up real well then take her through and if u got to wait in line more than like 2 cars drive it hard around the block again and hope the line gets smaller usually works for me good luck man.... Link to comment Share on other sites More sharing options...
Slick Posted June 28, 2006 Share Posted June 28, 2006 (edited) last time mine failed (dec) i had a blown head gasket...... and it barely failed. (i am in CA) and flew through with the new motor. like 88 said.. vaccum lines and the timing being out can play a big factor in what yer failing on and check for any loose/broken or parts that look to be old and failing 87 octane is all you need. if she pings check yer timing. these motors are emant and built to run on 87 octane. when you fill up throw some lucas fuel treatment in there.. i use it every other fill up n swear by the stuff.... Edited June 28, 2006 by Slick Link to comment Share on other sites More sharing options...
El Pathfindero Posted June 29, 2006 Share Posted June 29, 2006 What is this emissions stuff you guys keep talking about?? I live in SD.....not enough people to have 'em :cool2: Link to comment Share on other sites More sharing options...
Precise1 Posted June 29, 2006 Share Posted June 29, 2006 Yes about the 87 octane. Yes about running a tank of good injector cleaner before refilling and testing. Yes to cleaning/repalcing the air filter. Yes about EGR cleaning/testing, I had a similiar issue with a different vehicle. Yes to changing the oil just before the test, slightly heavier for an older motor cant hurt. Yes to having the motor HOT. With a new CAT and everything else you have listed, assuming all else is in good shape, it should pass... B Link to comment Share on other sites More sharing options...
John Boy Posted June 29, 2006 Share Posted June 29, 2006 Yes about the 87 octane. Yes about running a tank of good injector cleaner before refilling and testing. Yes to cleaning/repalcing the air filter. Yes about EGR cleaning/testing, I had a similiar issue with a different vehicle. Yes to changing the oil just before the test, slightly heavier for an older motor cant hurt. Yes to having the motor HOT. With a new CAT and everything else you have listed, assuming all else is in good shape, it should pass... B What would be a GOOD fuel injector cleaner there are so many of them on the market? Link to comment Share on other sites More sharing options...
congochris Posted June 29, 2006 Share Posted June 29, 2006 (edited) If you can find it, BG44K. http://www.bgprod.com/products/fuelair.html Edited June 29, 2006 by congochris Link to comment Share on other sites More sharing options...
5523Pathfinder Posted June 29, 2006 Share Posted June 29, 2006 Yeah, the BG products are pretty good. We use them at my work. They have a Air Intake System Cleaner that does a awsome job of cleaning the intake and valves of built-up carbon. And using the 87 octane gas, I tend to get a little worse mileage. I usually put 89 octane in and I use nothing but Chevron fuels if I can help it. Link to comment Share on other sites More sharing options...
Precise1 Posted June 30, 2006 Share Posted June 30, 2006 What would be a GOOD fuel injector cleaner there are so many of them on the market? Sorry... Redline is one that has been recommended several times and used in my 78 VW Bug, 95 Pathy and CBR1100 with no issues. Both the cars passed smog and seemed to run good. The smog guys at a local shop I know recommend using it before hand and they don't sell it... Timing, plugs and plug wires could have an effect if they are bad. I've only had 1 car that I didn't need to smog in 20 years. I consider myself experienced. I actually time tuneups around the bi anual smog gauntlet, milage depending... B Link to comment Share on other sites More sharing options...
mws Posted June 30, 2006 Share Posted June 30, 2006 Hopefully you've got through it by now... As I recall, high NOx is generally caused by high combustion temperatures. Other than producing hign NOx emissions, this is a good thing (within reason, of course). Things I can think of that generate high combustion temperatures at idle: - Ignition timing off (even a couple degrees can do it) - Malfunctioning EGR's - Problems with cooling system resulting in hot combustion chambers - Exhaust problems (restrictions or manifold leaks) - High compression (carboned up combustion chambers?) - Short duration, high torque cam profiles (not likely if stock engine) The HT383 in my van is famous for being difficult to pass NOx as the cam in it generates very high cylinder pressures for maximum efficiency and torque. Unfortunately, high temps come along with it. Link to comment Share on other sites More sharing options...
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