96 Sentra Failed Emissions, No Codes

Hi,

Wow. Frusrtrating. Been to the mech twice now. Here's the sequence of events :

Have been driving the car for years with check engine light flashing away, but this year has the infamous "emissions testing" has reappeared in my county.

Car fails emissions scan with state OBD machine ($41). Mech then hooks up his own scanner ( another $41 ) and gets code for EGR. He then finds rotted vac tube to EGR, replaces it. Retests car with his own scanner, and EGR code is gone. Good. But other codes , for things like cat converter, ox sensor, etc are "inconclusive".... Mech says he can't pass it with "inconclusive" codes; if he hooks it up again to the "state" scanner, it will fail, and I will lose my "one free retest" !! He then says I have to drive the car for several miles, and bring it back, at which time the codes for the other stuff should be set. Drove the car for 80 miles in town and on hiway, came back, mech retested the codes, still "inconclusive" !!

Another thing : The "check engine light" does not come on with the key in "on" and engine off. It only comes on when the engine is running. Sometimes it does NOT come on at all, and stays off completely while I drive, until I shut off the car and restart it, and then it flashes away happily once again.

Mech thinks the fact that the "check engine light" does not come on with "key on / engine off" means the computer might be hosed, and suggested I try a junkyard computer.

Would disconnecting the battery for a while help ?

Any ideas welcome !!!

Reply to
User132384
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Reply to
john smith

Reply to
MLD

Go pound sand. So far, all the mechs want to do is randomly replace parts until I get to the minimum ($150) and then give me a one year waiver. The damn state machine won't even tell me what is wrong. The SUV which passes the emmisions test is polluting more than my little 36 mpg sentra, dude. Like I said, go pound sand.

Reply to
User132384

Wonder how many other things this has destroyed?

Because driving around with the light on for years destroys parts like this.

Uh it isn't happy when it's flashing..

Easily could be along with dozens of other parts that got hosed while you're driving around with a check engine light flashing. What do you think "check engine" means? Ignore this light?

Reply to
Steve T

OK. Fixed the problem. The "self diagnostic screw" on the back of the computer was postioned almost all the way clockwise. I had adjusted it a couple years ago, and maybe it had vibrated into this position. Maybe I left it in theat incorrect position. Anyway, I put on my reading glasses and saw that the directions on the computer said that all the way counterclockwise was the normal position for operation. I turned the screw all the way counterclockwise and now the check engine light comes on with "key on / engine off" and it does NOT come on engine running. The computer was in "diagnostic mode" all the time, apparently, making the MIL light flash, although erratically.

Reply to
User132384

Great help - another tree-hugger! Let me guess, you're one of those who complains about high gas prices maybe? If all the tree-huggers had to pay about $5.00/gallon for gasoline maybe they would quit giving so much money to pass stupid laws. Maybe they would THEN be more willing to offer useful advice, instead of giving people a hard time about thier cars not passing emissions tests...

Maybe if we all end up paying 5/gallon for gas we'll start drilling for our OWN oil and not be dependant upon peoples like the Saudi's (who by the way pollute FAR more than most - you would not believe the crud they burn just to produce electricity...).

Reply to
Panther1

You are very naive. Follow this through: an international conglomerate like Exxon-Mobil drills a well in Alaska. They pump lots of oil. They either:

a. Sell it cheap in the USA at a price below the international or US market value because they like us so much.

OR:

b. Sell it like other oil on the open market for the best price they can get.

Note, before you foolishly choose "a":

- realize that any oil introduced into the market will sell at international prices

- realize that oil is not sold specifically for use in the USA

- realize that if they don't choose b, the stockholders sue and win

- realize that in the last round of price increases, while you and I were/are cringing at the pump, Exxon-Mobil reported record profits of

5 to 6 *billion* dollars on the price increases. (That's how much they care to help out US consumers. )

Reality check: The only one who benefits when oil companies drill oil at lower cost are the oil companies.

Reply to
- Bob -

Point, very well made... My response was however aimed at the individual who wanted to bash the poor guy originally seeking help for failing emissions.

You are absolutely right, and the scenario you present is something I had actually not even considered. Thanks for the enlightenment.

As for the guy who pounded the original poster - I have had a VERY WELL maintained vehicle fail Tennessee's emissions test. The same vehicle later passed after filling a tank that was one third full of gas containing about two times the amount of injector cleaner that was suggested for a thirteen gallon tank. No other problems were found after careful checking (the vehicle is a '91 Toyota Previa) and the computer gave no codes to go on.

Unlike the Nissan's which grace the drive, the Previa has no "potentiometer" that can be left in the wrong position. Kudos to the person who figured THAT one out. I didn't offer the person any useful information either, but rather was inflamed at the insensitivity of the guy who said "You've been getting away for years with a car the can't pass the emission's test. Pay the price to fix it or junk it." Really I should be adding value to the group, not lowering myself to the same level as the aforementioned... My apologies to the group for that slip.

Reply to
Panther1

Well, there is something wrong with the Previa if it won't pass. The injector cleaner trick is fairly well known and works in some cases. But, you do have an issue with that car.

Well, it does appear that the OP just drove around with a CEL for years. Foolish thing to do. The potentiometer actually has a function so it's a "feature". There's even a warning label on it not to leave it in the wrong position.

This is USEnet. Never apologize, just flame someone else! :-)

Reply to
- Bob -

well if you can say that the car is not passing smog because it is polluting...then MAYBE you can say he should stop driving it for all your grandkids health. but saying not passing because of inconclusive sensor readings and stupid procedures means polluting, is not the same thing. obviously this person wants the car to pass and save your precious babies. if you are so damn responsible go get fixed and stop having so many children! and if you are so concerned with the law make sure they are all registered for the draft!

for the person with the failing car...if you cant get it fixed maybe for your next car you can get something 25+ years old. clean or dirty they are smog exempt! then you will be a law abiding citizen haha

Reply to
captain bob

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