m,o,t, failier?

Question

hi there, my car has failed the m o t, on excessive carbon monoxide, and hydrocarbon. it drinks the petrol as well i mean £30 in tank gets me 170 miles its a rover 200 s reg, have chaged the cat and lambda sensor,but the lambda sensor was from our local car shop it did nt have the right plug on it i had to mach the wires and there was two white wires could this make a diference, cant think of nothin else it could be. help.

Answer 1

Hi there, both white wires are for the earth control, I might be wrong but I am sure that the black wire is for ecm control and the grey is for the plug heater control. The instructions supplied should have given you this info if you read them, If it came to the part where you might need instructions, surely the shop where you bought the sensor will have another sensor in stock and could give you a copy of the instructions. Another point, these cars are bad for the wiring chaffing through at the throttle body, just beneath it, these wires go to the injectors and this could be affecting injector duration, also check the temp sensors on the aluminium pipe at the right hand side of the engine.
There are more things that could cause troubles and these would need Rover testbook (t4)
Cheers

Answer 2

In most cases I have found that the simplest things help. Change the oil and filter using high quality fully synthetic oil. 5w/30 or 5w/40, even a 0w/40 if you want to spend the cash. ALL synthetic oils are quite pricey but well worth it. If you engine is worn e.g. piston rings etc. this will cause an emissions failure regardless of how new your exhaust system is. The common misconception is to put thick oil in the car. In fact its the exact opposite. Think about it, how is thick oil going to get up the sides of the pistons and help seal worn rings..? Dont go mad buying the most expensive either, Castrol GTX 5w/30 with racing stripes, a phat tail piece and boomin stereo is still just 5w/30 oil. The cheaper you buy doesnt lessen the quality it just means you can afford to change it twice as often...! Your last resort if this fails, and remember exhaust emission checks are free, is to go to Halfords or your local car spares place and get an OIL additive to seal the bottom end. There are a lot out there so choose carefully or with sound advice from someone whos had the same problem. If ( forte ) make one then go for that as their radiator sealant is beyond belief. The wires to the sensor will have no outcome in your scenario, but pop into kwik-fit or summit and theyll steer you right. Sorry to be so long winded but hey, Im only trying to help.

Answer 3

The lambda sensor must be an exact match to the part you are replacing and if there are spare wires it is the wrong one. Try a genuine part from an authorised Rover parts supplier. The wrong sensor may be causing your high emissions but there are many other factors to consider such as servicing and relevant components ie: your cars recent service history, fuel and injection system etc

Answer 4

I think you've answered the question yourself - you fitted the wrong Lambda sensor