Hilux 4x4 Forum

Hi everyone. I am looking to buy a 2009 prado 150 4.0 V6 VX. 113000km. Excellent condition. Just one problem.... the exhaust and the manifolds have been swopped out for a performance system and the catalyst removed. The lambda sensors are only on the one pipe from the head on each side and not after all 3 pipes converge like on the original manifold. Normally 4 lambda sensors but I could only see the 2. Not sure if the other sensors after the cat are still there. The fuel smell from exhaust is very rich upon start up. No lights on the dash to indicate any engine problems. I was told to stay away from the vehicle as it will be heavier than normal on fuel consumption.....and that it may run into problems later. The previous owner is not reachable for comment and the vehicle is sold from a used car dealer. Any advice would be appreciated. Please delete this if not appropriate on this group. Thank you.[IMG]//uploads.tapatalk-cdn.com/201707 ... 133abd.jpg[/IMG][IMG]//uploads.tapatalk-cdn.com/201707 ... 5eba70.jpg[/IMG]

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Normally the guys remove the catalytic converters to improve gas flow through the system and in so doing improve the performance (efficiency) of the engine. The lambda sensors are replaced with mini units so as not to get faulty readings resulting in error codes on the engine management system.

The thinking is that if the engine produces more power due to more efficient airflow it has the potential to be more economical but in practice people tend to use the power.

The lambda sensors that are used in standard vehicles are normally narrow band sensors and only function at idle anyway. Wide band lambda sensors are much more expensive.

The mixture will smell rich when cold as the cold-start circuit will be in operation which enriches the mixture in the absence of a traditional choke.

Hopefully some of the guys with other V6es will chime in here regarding their experiences in removing the cats and the effect on fuel consumption.