I have a rhz engine in my car, which starts and ticks over as it should, but when I'm accelararitng heavy I get thick black smoke and you can also hear a kinda ticking/clicking noise, it wil do this right from when the turbo comes in at about 2500rpm, most of the time the car will b ok after this but if it happens when the car is uner more load ie going uphill the EML will come on, I've plugged it in to a snap on brick and its showed 2 differnt codes, boost pressure low and over boost? my mechanic hasnt a clue and the only thing I've founbd was 1 of the vacuum pipes was blocked, also just t notewhen the EML is on there is no smoke up to 3000rpm and no ticking/clicking noise so what would get turned off when limp mode is active?