Thank you very much for the detailed reply. The car is pre OBDII, so I can't read any meaningful codes, unfortunately. I don't have a Pico pressure transducer, it sounds useful, but the price is too much for the occasional road car work I do. I have a wide range of pressure transducers for race car after market ECU's, for use as MAP sensors, boot pressure sensors, fuel pressure sensors, etcetera. Not wanting to turn this into a DIY forum, or offend anyone, would it be possible to feed a suitably ranged one 5V and ground and read the signal wire via the Picoscope, with it connected to a smallish bore tube shoved up the tailpipe? Yes, I know, I should just go and buy the nicely encased, proper tool, but for the amount of use it would get, it is probably make something temporary, or work without one altogether
Again, thanks for your time Robski.