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i had the car for its 20k service - the car is 6 years old and has 70 000km on the clock and 20 000km on the engine - new engine - dont ask why!:tut:

Once the machie done the diag only one error code jumped up:

P1155 Preheating resistance 2 above catal.

I've got a straight through exhaust from after the cats with only 2 boxes.

Could this be it, the machie couldn't tell me what the fault was....hhhhmmm:wow:
 

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even with de-cat you must still have the lambdas conencted or else by-passed/simulated?
 

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i have a new manifold without the two pre-cats and im getting the same message.
wiring is correct.
new lambdas fitted.
I have a manifold without the two precats and 200CPI main cat and I am getting no error codes. All lambdas and wiring is kept as original.
 

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200cpi here too. maybe its due to the sensors being aftermarket ones?
It may be the cause. How did you install them? Soldered them on? Once I read some Bosch paper for the garages how to install universal/aftermarket lambdas, there was some special way how to connect them as Bosch said the soldering changes the resistance in the cable and the lambda reading is wrong. Actually orginal lambdas as replacement pars for the specific vehicle are precisely calibrated for the length of the cable and its resistance from sensor to the connector.

But the P1155 code is relevant to the lambda pre-heating feature, not the actual lambda reading. Are your aftermarket lambdas pre-heated? If they are not, ECU is probably looking for some value on the pre-heating pin of the lambda what it doesnt get. My guess....
 

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But NTK and Bosch lambdas have different resistance ratings. I found it somewhere on the web ages ago that NTK were 4 ohm and Bosch 8 ohm. It there are others, I bet these are different too.

I've got a Bosch universal in the garage waiting to be fitted when (a) it's warmer and (b) I can get the old lambda out! In the instructions it clearly warns NOT to solder the wires but just used the connection block provided in the kit. These are screwed in cable clamps so you just trim the wires back as specified and clamp them in.

The actual lambda sensor on my 156 is the same as a very wide range of cars .. all that differs is the connection plug and length of cable. So I got my Bosch universal lambda from a Vauxhall parts web site for around £50.
 
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