The engine revs drop when it reaches running temperture

P2097 code has two fault locations. 1) post catalytic converter fuel trim (FT), bank 1 - too rich. possible cause Catalytic converter. 2) Heated oxygen sensor (HO2S) 1,bank 1 range/ performance- circuit low. if it's running fine. probably just need to put an oxygen sensor in it.

I recommend having a shop take a look at it. It could just be the O2 sensor, or you really could have an injector putting too much fuel in one cylinder. A mechanic would watch the data stream coming from the sensor on a scanner to judge if the sensor is working or not.

code p0172 refers to system too rich bank 1===causes --intake blocked (air filter) EVAP canister purge valve---fuel pressure---EGR system--injectors--HO2S (oxygen sensor). The first thing to check would be the oxygen sensor and air filter. Then check the fuel pressure in the fuel manifold to check for fuel pump/filter/ pressure relief valve that may be causing an injector fault

Sounds like a coolant sensor problem. It signals the ECU for open loop, cold start rich, high idle, until warm up is reached.

A rich codes is hard to get. Something is restricting the airflow or you have something wrong with the fuel control. Check the air filter and if it is good. I would wonder if you have a leaking fuel injector. Do you know how to do a cylinder drop test? How well does it idle? Does it smell of raw fuel at idle? Is it hard to start after sitting?

RICH MEANS TOO MUCH FUEL.........OF NOT ENOUGH AIR? ANY OTHER CODES?

have the computer checked for a fault with the throttle position sensor(tps)It does not always trigger the check engine light.I am not sure if there is an easily hired or purchase fault code reader for this model.You may have to go to Jaguar centre for this.Throttle bodies should be clean on this model.hope this helps or get back to me with findings.

WELL WHAT ENGINE HAVE YOU GOT I know it must be either a V6 OR V8 and if the right hand bank of either 3 or 4 plugs leads are taken off and it still keeps the same and it dosent make any differance to the revs etc then it got to be a gasket on the inlet manifold on that head so that no petrol vapor is getting as it is sucking air only..
But what i carnt work out is how it run correctly on the Left hand bank only (IT CARNT)
There was a Army truck 1 tonner years ago that was a v8 and they had it to run on 1 bank of 4pistons {as a 4 cylinder engine} and after 150.000 miles they would take the old pistons out and fitted 4 more to the other bank and they kept running 100%.. but you havent got one of them sorry to tell you.. So let me know the answer to all above Ron

it sounds like the O2 sensors need replaced. bank 1 is the left side and bank 2 the right

is the software reading the fault right ??