k9sar

Ok... so here's the deal. My 95 pathy has failed emissions testing Symptoms: The pathy seems to idle fine and run fine during accelleration but has a bit of a dead spot in the power band when cruising along steadily at 2000 to 2500 RPM. Almost like it's choked... hesitation, a bit of sputter, etc. Does not stall but does not respond immediately if I hit the gas. On occasion, after prolonged driving, the CEL pops on with a 33 code (O2 sensor). Once this occurs, she runs rougher and it seems like I have to try to keep it running although it never stalls. Obviously, the brain is trying to compensate for something and making it run worse. I can stop, clear the code and it runs fine for awhile. I do not think I am getting good mileage but that is expected if running rough. My temp reading stays barely above the bottom of the guage even when a 70 degree day running hard. Test readings: 2007 test: CO% .62 (limit is 5.4) --- HC ppm 283 (limit 537) --- NO ppm 851 (limit 7380) --- 14.7% dilution at 1897 RPM 2008 test: CO% 20.55 --- HC ppm 882 --- NO ppm 234 --- 17.5% dilution at 1842 RPM ----> RESULT... FAILED In addition, the O2 sensor threw a code during the test. So... based on the FSM, I tested the O2 sensor circuit and got good voltage on the appropriate pins. When I tested the resistance across pins a and c (at temp) I read 4 ohms. Spec range is 3 to 1000 ohms. (anyone know what a new one reads? Is it on the low end or high end of range?) These readings lead me to believe that the O2 sensor is good and it truely is detecting something like it should. I pulled my disty cap and preplaced it with my old one that had no issues passing inspection before I swapped the motor. I replaced the rotor in the disty with my prior one as well. Again, the old motor never failed inspection. I pulled the plugs and noticed the electrodes were burnt down so I replaced all 6 plugs with NGK's as recommended inthe FSM. side note, make sure you blow all the mud and crap out of the plug holes before removing your plugs. Mine sat in caked dirt halfway up the insulator. I checked the resistance of each plug wire and they are well within spec. I checked to see if I had good spark and found that it could easily jump a full inch from the plug to the intake manifold I was using as ground. With that much spark, I should be able to run with virtually no electrode or arm on my plugs. Replaced the plugs anyway. I pulled my air filter and shook it. About a half cup of crud fell out. I blew out the intake and air box and replaced with a new filter. She seemed to run better after that so I sent it back in for a retest 2008 test: CO% 21.54 --- HC ppm 699 --- NO ppm 684 --- 17.7% dilution at 2716 RPM ----> RESULT... FAILED Obviously there is something that has failed that is causing increased CO and HC readings. I thought that running rich would only increase one of these but I forget which and could certainly be wrong. I don't want to start replacing parts at a hundred bucks a shot and hope to happen upon the failed component so I am looking for real and knowledgeable information which would lead me to a solution. Who's the former nissan techie in here? The mechanics of the O2 sensor are that it compares exhaust gas with outside air to make a determination of problem. Even though my test readings are good, could it be that the O2 sensor hasn't liked being submerged and caked in mud many times? It was also suggested that my eng temp sensor could cause the ECU to run differently (change spark advance etc?) and may also explain the low temp reading. again... I don't wanna just throw new parts in until it works. If you have any knowledge of this type of situation and can steer me in the right direction for a solution, I'd certainly appreciate it. Thanks

yea.. with a caR50, I'd put heavy odds that she's toast.

hehehe. forgot about that.

besides the phone holder, cup holder, and cookie-tray flooring, I redid mine in a fine layer of mud and dirt... expecially around the passenger side window

my pathy leans left when I drive it. Prolly due to all those burritos I've been eating

you can probably go to Home Depot or similar and get some shower pan liner and cut your own

yea, I'm thinking EGR as well.

well... there ya go.

what he said.

I have never seen the knock sensor actually go bad. Usually there is a different problem that makes your truck try to overcompensate for and run sh!tty, thus causing the knock sensor to detect.

in 95, the roof rack and wind deflector was standard on the SE and LE versions. The XE was wingless.

I buy the cheapest thing that has a lifetime warrenty at Advanced Auto. If it fails, I get a freebie (just did one on my van)

I is an enginerd

I think I have an extra dip out of my 95 swap. My suggestion is a strong magnet. See if the tip fo the dip is magnetic. If it is, then when you drain your oil, slide a magnet around on the bottom of the pan and try to draw the piece to the drain hole.

condensation in exhaust etc. Also, if an engine has been sitting for a bit, there could also be some in the cylinders depending on open intakes and humidity at the time it was shut down.

if you had a blown head gasket, you would be generating big clouds. Been there. My pathy blows white for a bit after sitting for awhile. just steam as far as I'm concerned.

yea, even a single gear off will cause you trouble with the distributer. You can get her to run but you won't be able to tune it into the required timing. Go slow when removing and reinstalling the dist. It's easy to fruckup.

check TDC by pulling out plug 1 and putting a long screwdriver down the hole. disconnec the coil and hand crank the engine until the piston is at the top. Check the distributer. It will either be at post 1 or 180 degrees off. and check the plug you pulled... if it's dry on the electrode, you ain't getting fuel. Should be wet with gas if you are cranking and the fuel injectors are working

next suggestion would be to get yourself a chickenbone cross, some river stones, a lighter and a live platypus....

not sure what you mean by 'other post' There is a single big wire on the starter that holds 12V all the time There is a smaller wire that connects to the solenoid (on the side of the starter) that is tied into the ignition circuit. Turning the key energizes the solenoid which throws the big wire 12V to the starter windings. Check for 12V on the big wire. Check for 12V on the trigger wire in all key positions (off -> 0v, on -> 0v, start - 12v) if voltage isn't there, the problem is upstream and could be the connection to another relay that has baffled many and bypassed by few. I have a writeup in here somewhere about how to bypass the intermittent starter issue.

looks like a garage door handle.

typically you should address the first code first. I get the knock sensor code when the damned computer adjusts my mixture too rich or lean due to some other error like the O2 sensor etc.

that's good to know. Next time I need to get at mine, I'll try that method

Don't really see any change with RPM. Will change the thermo and take a whack at flushing the HC. I wonder if I can swap the hoses and run it backwards... hmmm... I'll have to think about that. In theory, should unblock whatever may be blocked. Of course, then I'll have to drain and flush the entire system.

nope... full to cap and half full in burp bottle.