mobile diagnostics in south wales

[a13bhw]

hi guys ,can u help .ive a year 2000 lexus gs300 just changed engine,and ive a misfire, can anyone tell me who to contact in s wales,as I live in Merthyr Tydfil.basicly its pre obd 2,as being year 2000.it just needs a diagnostic and error fault finder thanks brian.looked on ebay for pre 2000 obd1 but its easier to look for obe wan kanobe.