sounds like teh same probelm i had the stu diagnosed as a faulty map sensor, really rich at idel and misses dur to exxessive over furlling at teh revs increased yet teh reading from teh mapsensor on teh pectel monitor was as per spec, stu swapped it after we had tried everyting else to no avail, and hey presto, it worked 100% yet the pectel monitor was reading exactly the same value... - strange but true