the 1999-2003 trucks use a frame rail mounted electric fuel pump. The 1999–2003 trucks also had a deadhead fuel system and a "long lead" injector in cyl. number 8 due to lower fuel pressures with the deadhead design (AE code injector). The California trucks from 1996 and 1997 have a split-shot fuel injectors; other trucks did not get split-shot injectors until 1999. Single-shot injectors only inject one charge of fuel per cycle, whereas the split-shot injector releases a preliminary light load before the main charge to initiate combustion in a more damped manner. This "pre-injection" helps reduce the sharp combustion 'knock' as well as lower NOx emissions by creating a more complete burn. The '94.5-'97 engine utilizes a single turbocharger, non-wastegated, with a turbine housing size of 1.15 A/R. In 1999, an air-to-air intercooler was added to cool the charged air from the turbo for increased air density. With the new cooler, denser air would increase the horsepower potential of the engine, while also reducing exhaust gas temperatures (EGT). The turbine housing was changed to a .84 A/R and a wastegate was added halfway through the 1999 model year. The 1999 engine also received injectors, up from in the early model engine. With the larger injectors, the HPOP capability was increased by utilizing a 17° swash plate angle to meet the requirements of the new, higher flowing injectors. The engine used forged connecting rods until powdered metal rods were introduced for early 2002 models. Serial numbers can be seen with the aid of a borescope to confirm the changeover between the 2001 and 2002 model years. These new connecting rods sufficed in an unmodified engine, but would become a potentially catastrophic failure point if aftermarket tuning pushed the engine above . Early models did not use any form of exhaust aftertreatment, such as a catalytic converter, as emissions were not enforced on diesel motors; however, by mid-year 2002, Ford began installing catalytic converters as part of the OEM exhaust as part of the Tier 1–3 standards. Common issues Despite being regarded as one of the most reliable diesel engines ever put in a light-duty truck, the engine had its own issues. A common failure point was the camshaft position sensor (CPS). The failure of this sensor would cause a no-start condition or a stall while running. The easiest way to diagnose a failed CPS is through movement of the tachometer