I have recently had a tune done on 14psi, If I was to raise my boost 1 or 2 psi to say 16psi, would I need to get the ecu re-tuned or would it be safe to run as is without the need for a re-tune?
It would all depend on how the car was tuned @ 14psi. But I would play it on the safe side and get the car on the dyno and then crank it to 16psi to see what the AF ratios are like.
Yes.... Get wide band o2 sensors connected to your exhaust and the appropriate guages to measure the AFR's. - would be cheaper and quicker to just pay for half an hour dyno time and do it properly.
conzult will monitor the standard narrow band o2's which will just show as RICH (which could be anything below 14.7:1). You'd need a wideband O2 installed so that you can accurately monitor AFR's but it's probably cheaper to just do it on the dyno.