Volkswagon carravelle failed m.o.t on gas emmisions tried lamba sensor no improvement any ideas. 1995 model

P0430....Catalyst System Efficiency Below Threshold (Bank 2) I cannot answer other codes without model and make ...but looking at this code alone i would suspect you have a failed lamba sensor therefore i would advise you seek the help of a local garage recomended to you by a friend or neighbour Because the emmisions will be high causing polution that pedestrians will be breathing in .Plus the extra fuel your using is costing you money

Well like you say ( lamba) means o2 sensor and cat .... New ? Co2 too much gas it could be bad fuel injectors ..... Check for codes the ecm have the most important info about it

Air fuel mixture may be it. Also it could be a bad catalytic converter. Also the timing may be the culprit.

connecting to the OBDII is not part of the test ,the emmisions are tested by putting a probe up the exhaust pipe and running engine at 2500rpm then the CO and lamba are checked on a gas analyser .

Not familar with american motors but i would hazard a guess and assume they are for the lamba sensor ,now the 2 white wires sre for the heatrer on the sensor so they can be connected anyway around but the 2 tan wires have got me as a lamba sensor uses two different colours for the filament in the sensor a gray and black is normal but it can vary although i have seen two black and two grays on some replacement sensors so just connect them up and if iam correct it should work providing that this is the lamba sensor wires you have cut through ,if iam right and the engine symbol light comes off reverse the two tan wires and clear the fault code and try again

could be one of two things either your cat is failing or the lamba sensor on the cat which measures gasses in the exhaust system has failed which will illuminate the light on the dash

o2 sensor, or some other emmisions sensor

IF YOU ARE GETTING A THROTTLE PEDAL POSITION SENSOR FAULT CODE.THE THROTTLE POSITION SENSOR IS THE WHOLE THROTTLE BODY UNIT IS THE THROTTLE POSITION SENSOR.THE SENSOR NOT IN GAS PEDAL LIKE VOLKSWAGON. VOLKSWAGON HAS THE ACCELERATOR PEDAL POSITION SENSOR.

possibly the float in the gas tank. the float and the gas pump come as one piece on most cars.

Very common for the coil pack to fail on this model, also the plugs are a pain to change and are often left, try these first.