Why ? Is The Car Work Better When Boost Sensor Not Connected

[gttiwanna]

As the title said I have been having problems with my car and boosting past 5000rpm it hits like a boost cut but I realised that it only started happening when I put a new boost sensor on the car so I disconnected the vacum hose and now the car runs perfect how is that worked ?

Anyone ? Lol

Car is r34 neo turbo

Fmic pod and cat back did it on both manual and standard boost control

[Moodles2]

What kind of boost sensor, factory for the stock gauge, aftermarket for aftermarket gauge etc?

[gttiwanna]

Factory one and its not just for the gauge in the car other wize when I disscconet the plug it would do nothing but the engine check light comes on so has to do something

[666DAN]

You mean the one on the firewall in the centre? That prevents the car from overboosting...so basically your boost was peaking higher than the factoey cut-off point (safety feature)

When it's operating properly, it cuts fuel at 4.7v reading

If the car has been checked on a dyno to check the fuel ratios at the increased boost, then it's fine....if you've never checked it, get it checked ASAP

The reason the engine light comes on is the fact this is a critical sensor, it regulates the idle and off-boost fuelling. With it disconnected the car defaults back to a guestimate map to allow you to drive, economy will not be as good.

A quick cheat is to run a small signal diode in line with the green signal wire on the sensor (make sure the diode is the correct way to allow current to flow) this will chop between 0.3 and 0.7 volts of the signal and allow you go slightly past the factory boost cut. Yet keep the engine safe if something went wrong and the car free-boosted. You may need just a 1 diode possibly 2 in an extreme case.

[gttiwanna]

But It's on stock boost the only mods I have are full exhaust and fmic and pod

What would it make it hit boost cut ? Boost sensor gone ? Afm?