Im just after a bit of advice.

On all of my previous cars I have always removed the catalytic converters (legal where I live). I want to do this to my 3.2 X300 but I just need to know if this is going to cause any issues, potential check engine light etc. Please let me know your thoughts.

 

Hi Adam i removed my cats from my 1997xjr 300; and made up my own exhaust and refitted sensors one year ago . No problems to date

 

I have removed the front cats and have a new pair under the floor where the old underfloor one where throws no codes

 

You guys can get away with this because you have "two oxygen sensor cars". Those of us with "four oxygen sensor cars" ....North American market and perhaps a few others....would be looking at a check engine light :-)

Cheers
DD

 

A lot of cars run that two-O2-sensors-per-cat system nowadays. You can get rid of the "check engine" scenario by replacing the downstream sensor with an O2 Simulator for about $100.

 

So am I correct in saying that on non US market cars there are 2 oxygen sensors? one visible from the engine bay and one near the middle of the exhaust?

 

U.S. and U.K./Ireland models at least have an oxygen sensor near the exhaust manifold, which is used to send information about the O2 content of the exhaust gas to the ECU, which keeps the air/fuel mix adjusted accordingly. This is also known as the Lambda sensor, or "upstream" sensor. There is a second sensor after the exit end of the cat - known as the "downstream" sensor - which provides a second O2 level reading.

The idea is that since the reaction inside the cat consumes oxygen, the reading from the second sensor should be lower. If it isn't, then the computer concludes, reasonably, that the cat is malfunctioning. So when the cat is deliberately removed and this second sensor is present, it needs to be seen to or else you live with the "Check Engine" light. Of course on cars with two manifolds (all V6/V8 and most straight-six Jags, for example) you have two cats and therefore four oxygen sensors.

I'm a little surprised to learn that they are/were sold in some markets with upstream/Lambda sensors only?

 

The second sensors are located behind the second set of cats and are there to tell the ECU to turn on the air pump to warm up the rear cats quickly in open loop mode when cold started started
I don't have the air pump either runs very nice and will never ever crack a manifold or anything else the standard exhaust system on these cars is pretty crappy especially after 18 years of usage

 

thanks for the advice. My other cars only have 1 oxygen sensor so it's surprising to me the (relative) level of complexity adopted by Jaguar but I guess that' due to the whole emissions concern.

 

You can thank Ford Motor Co. for that.

 

Just to be completely clear on this, the O2 sensors are paired, one for each bank/branch of the exhaust. UK cars only have upstream O2 sensors, one for each bank/branch of the exhaust, 2 sensors in total. US cars have upstream and downstream sensors, one for each bank/branch of the exhaust, 4 sensors in total. Rest of the world, take your pick from these two set ups.