volvo 740 gle lambada sensor missing ?

please help i have a volvo 740 gle saloon,,,,im not sure wether it has the b230f or b234f engine fitted , (id plate on timing belt cover is missing),,,it has the self read onboard diagnostics if that helps,,,, i keep having problems with the emission warning light coming on , ( which i reset by disconecting the battery ) i have tried to solve this problem myself for a long time now and im getting nowhere . i had a full exhaust fitted incl cat 2 years ago and im sure ,,,in fact im certain the original exhaust had a lambada sensor fitted with two wires on it (may have been 3),,,having had a good look round the downpipe cat etc there is now sign of this on the exhaust that is now fitted,,,,my question is this,,,,,could the kwikfit centre i used have put the wrong exhaust on ,,,,ie,,,,done away with the sensor,,,and if so is this an acceptable modification or just a lazy **** job,,,,and if so what problems would i have ?,,i understand my car has the LH jetronic injection system fitted and my understanding is that this system relies on the info from the lambada sensor to operate properly , many thanks for reading my post,,,,any help would be appreciated,,,and if kwik fit have pulled a fast one i will be banging on there doors 1st thing in the morning thanks gav

I'm not sure if they had on your car or not, I can look it up if you let me know the year of the car though.

Fitted a system without the lambda probe is ok provided the customer knew about it and was happy with what was involved. To be honest there was no reason for them to omit the lambda probe as if the replacment down pipe did not have the boss they could have cut the one off the old system and used that. The lamda probe used on your car will be a 3 wire 0 -1 volt probe (2 x white wires for power and earth and 1 black wire signal). If they are replacing it I would ask for a genuine volvo one as that is what was on the car and some cheap after market ones don't last very long. Also cheap probes tend to come without a plug and the wires have to be joined. The lambda probe wires are stainless steel and have to be silver soldered. Crimp on connectors do not grip the wires and will pull off. The odd thing is usualy removing the probe does not cause the light to come on but if it was left hanging that would do it. The wires for the probe are on the engine bulkhead RHS. You have the single black wire on a spade connector and teh two whites are on a plug the same shape as that used on teh fuel injectors.

The emission warning light covers a broad range of faults, not just limited to the lambda sensor... Read the codes on the OBD to determine the actual cause of the light before attacking kwik fit... Also, I would say that seeing as the car passed the MOT emissions test ok that the cat was not affected until at least recently...

Good morning Gav, your engine should be B230F, the 16valve B234F was released in my89. And for OBD checking I always thought was not avaliable then, I got surprised! But in fact, if B234F is LH2.4 Jetronic, maybe yours is the same. As for the lambda sensor, it is to keep nearly-to-stoichiometric ar-fuel mixture. Failing, it will make cat work harder, and damaging cat on a (very) long term basis. But it doesn't mean you cannot run it, i believe CO limits are some 3% vol for 1988 vehicles, so maybe MOT check ok.