I've been trying to get my 94 xjs 4.0 smogged. It has been running rich, you can smell the fuel. My car has tags until 5/12 though I cant transfer the reg until I smog it so I've been driving it with an incomplete reg. The DMV guy tells me this is ok but I just cant sell the car, which is fine with me cause I want to keep it. So I can drive the car until 5/12...

The first time I brought it in it passed for no2 but failed for co2 and hc. I replaced the oxygen sensor which was covered in oil and I also replaced the egr valve, just because I found one for relatively cheap ($50). The EGR valve fixed an issue I had with the engine dropping in rpm when I hit the brakes (which is a very nice fix btw).

TOn the second test I failed for no2, co2 and hc. The co2 and hc came down a hair but the no2 shot up. It seems a new egr valve would bring down the no2?

The smog guy tells me that for some reason jags have tough requirements. he said the requirements are that of a honda running very well. Any other CA owners run into this or this guy bs me?

Im confused about the new egr and o2 sensor causing things to get worse. One thing I did after the first smog, which may be one of the the culprits, is I put a resistor on the Ambient Air Intake Sensor to get it closer to the actual temperature (it was reading hot). It tests ok now but maybe that offset the new egr sensor and o2 sensor by causing the car to run even richer?

It seems that I also may now have burnt out the precats since the car runs rich. I drive it everyday. I dont mind replacing these if that is the most likely problem.

Why is CA making it so hard for jag owners to pass?

Btw, the thing runs and drives like a dream. Compression test is good. 162-172

 

California is the land of restrictions! I have a V12 jag I'm trying to sell so unfortunately I can't offer any advice except share the frustration of getting a jag to pass smog. To get mine to pass I had to replace all o2 censors. I dot know why California has to make it so hard to pass smog with older cars.

 

Yup. This state is something else sometimes. I would never encourage anybody to do this, but its pretty well known here in SJ that about $150 can get you smogged..............regardless of what the readings were. Just have to ask around I guess. Id try the east side of town first lol, prolly wouldnt take long either hahaha

 

I nioticed that 1994 is the cut off year higher emissions standards (obd2). Even though my car is obd1 technology. It turns out that if I had a 93 xjs, it would pass no problem, as my readings are in the pass zone for a 93.

Technically the car should be allowed through since it is OBD1 and the car actually was built in 93... I agree with making more efficient cars and making sure that cars maintain there smog limits within reason. It doesnt make sense to penalize people who bought a car that blew emissions out when brand new. If anyone gets penalized it should be Jaguar for not getting quick enough up to standards in 1994. Trucks over 14000, get by without needing any emissions tests. It makes no sense. Its quite asinine.

I had a guy offer to get it through if I paid him a couple hundred. Im going to try one more time to get it to pass, if I can get a new CA cat for the price I found listed online ($90). I dont believe that I need to get the precats replaced as they are only effective when the car is cold, to my limited knowledge. Correct me if Im wrong. Eventually, when I can afford it, I am going to do the precats. Not because CA forces me to, just because I would like my Jag to be less of a polluter for my own ethics. I may even convert to propane, but thats another thread.

 

I just passed my 86 XJS on Tuesday with flying colors. it'll be 5 years that iv had it. and shes has passed the smog each time really easy. I was a little scared this year since its been 2 years since it was tested. all the emissions were very low.

 

Shawn, do you know what kind of actalytic converter you have on the car? Is it the original? Precats?

Im trying to make sense out of catalytic converters. The prices are all over the place and a converter made for engine/ weight that is 5.9 liters and 6000 pnds, is half the price of a converter made for the jag xjs (4.0L/ 4000pnd max).

I would rather go with a bigger converter made for a 5.9L and have a little more restriction (which Im sure would still be better than the old cat on there, technology has advanced), and be sure to pass smog for the next five or so years. Anyone know the logic behind cat converters, the pricing, why its illegal to go by size of engine and weight of vehicle when choosing a converter? Would going with a larger converter be better for the environment. Are CA politicians smoking too much weed?

If you look at this site and compare pricing there is absolutely no logic to it:
http://www.performanceexhaustplus.co...-only-119.html

 

i think the original cats are in mine.
those thiings are expensive!!!

 

Ca politicians aren't smoking enough weed!!! I was hoping Jerry Brown would change that!!

It is pure BS that even if your car will pass all the smog test it will fail because the smog junk isn't on the car. I have an old Scout and it failed due to the gas tank not holding pressure, old leaky smog hose. They take off the gas cap and put 4 lbs, not sure exactly, of pressure on it. not expensive to fix, just time consuming to find the leak.

I just bought a '90 XJS V12 yesterday and it was just smogged last month, hopefully I won't have to re-smog to register. All of the reading were well within the limits so I am comfortable if I do have to re-smog.

 

I'm grateful to live in a state that has no smog rules for vehicles prior to 96. I don't even have cats on mine!

 

@Terry had to give you a thanks for that one. Good to know im not the only one who lights one up and checks out this forum

 

I might be able to help. I was a CA smog tech for 6 years before joining the Marines.

this is bad, as ill explain

can you get the the numbers for the smog test? what your PPM was for NOX and HC, your precentage for the other gases?


um no. Jags dont have 'tough requirements' and the ones it has are low because when the engine runs well it runs clean. Standards are set based on type of car(ie truck, small pass, etc) and the model year.

Cats and precats will burn out. HC (which is unburned gas) reacts with the elements in the cat on a molecular level and melts them. So if your able to smell gas from your tail pipe then your running rich, very rich, and your cats more then likely toast. Sorry. With new O2 sensors and no check engine light Id check the computer. Its difficult to diagnose it without hands on and an emissions machine.

As for the price of cats being so different and varied and making no sense...Manufacturer, size, style, and moutning options. Some of the cheaper ones are smaller, and weld on. Others have the mounting tabs for certain size exhaust pipes while others are a size and shape to it in odd spots under cars that dont have much room. They may also come on a length of pipe that is bent to fit a certain model of car.

As a smog tech we have to put down what kind of repairs we did to a car, if any, to make it pass smog. This info was recorded and passed onto the state. If a smog tech always replaced the cats, then he was investigated. The reason being that cats will clean up most anything. For a short period of time. They are the universal 'band-aid' for emissions. You didnt hear this from me but if you want to pass smog, and your car is running good, then replace the cats and take it in right afterwards. Guaranteed to pass unless something is seriously FUBAR with your engine. Street racers would take a new cat, bolt it on, drive to a smog shop, ask the tech to leave the hood down and run the test. Car would pass the emissions with flying colors, they drive home, take off the cat, and save it for next time. Or so ive heard.

 

[QUOTE=hoodun;434799]I've been trying to get my 94 xjs 4.0 smogged. It has been running rich, you can smell the fuel. My car has tags until 5/12 though I cant transfer the reg until I smog it so I've been driving it with an incomplete reg. The DMV guy tells me this is ok but I just cant sell the car, which is fine with me cause I want to keep it. So I can drive the car until 5/12...

The first time I brought it in it passed for no2 but failed for co2 and hc. I replaced the oxygen sensor which was covered in oil and I also replaced the egr valve, just because I found one for relatively cheap ($50). The EGR valve fixed an issue I had with the engine dropping in rpm when I hit the brakes (which is a very nice fix btw).

TOn the second test I failed for no2, co2 and hc. The co2 and hc came down a hair but the no2 shot up. It seems a new egr valve would bring down the no2?

The smog guy tells me that for some reason jags have tough requirements. he said the requirements are that of a honda running very well. Any other CA owners run into this or this guy bs me?

Im confused about the new egr and o2 sensor causing things to get worse. One thing I did after the first smog, which may be one of the the culprits, is I put a resistor on the Ambient Air Intake Sensor to get it closer to the actual temperature (it was reading hot). It tests ok now but maybe that offset the new egr sensor and o2 sensor by causing the car to run even richer?

It seems that I also may now have burnt out the precats since the car runs rich. I drive it everyday. I dont mind replacing these if that is the most likely problem.

Why is CA making it so hard for jag owners to pass?

Btw, the thing runs and drives like a dream. Compression test is good. 162-172[/QUOTE
where are u located did u find any mechanic to fix it because I having same problem didn't pass smog check and i need to sell my jag 93

 

Hoodun - your car should have 4 oxygen sensors. I would replace the other 3 and see if that helps before you do anything else.

 

Cant Fart in California without an Air cleaner strapped to your ***.

 

One trick that might work is to run the tank somewhat low and then add a gallon of denatured alcohol, then take it for the test. This works only if you have a tail pipe test.