This 2003 Dodge Ram 5.7 V8 Hemi p/up truck is owned by a Customer of ours. The engine is a unit used in other Chrysler/Jeep models. He had an LPG dual-fuel system fitted 2 years ago by persons unknown to us. When changing-over to gas it registered a fault in the ECM illuminating the MIL (malfunction indicator lamp). This did not cause driveability problems but it was rather annoying having the lamp illuminated whilst driving until the ignition switch was cycled & the system reset. A diagnostic scan revealed a fault code relating to a fuel injector misfire. This was caused by the fuel change-over duration, controlled by the LPG system ECM being too slow & the OEM ECM picking it up as a fault. This was confirmed during a fuel change-over whilst the diagnostic equipment was connected giving a live data read-out. Whilst the ECM was busy giving out the data to the equipment, it slowed down the ECM processor enough for the change-over to take place without it registering a fault. We also found the LPG nozzles fitted into the composite inlet manifold had become loose creating an air leak & causing the engine to run lean whilst running on petrol. This may have been the cause of the cracked & warped exhaust manifolds which had also forced 5 manifold retaining bolts. Unfortunately these were not accessible with the engine in place necessitating removal. The engine had not weathered well in its 7 years being badly rusted & corroded. The vehicle had quite a few other mechanical problems. The Customer’s instructions were; remove the engine & ancillaries, clean & derust, remove broken exhaust bolts & carry out thread repairs as required, prime & paint. Following this, refit engine/ancillaries with new stainless steel headers, new stainless steel exhaust system, carry out remedial work to the LPG system, fit new steering rods & ends, new upper & lower front suspension ball joints, new shock absorbers all round & new alloy wheels & tyres.