The 1401 code is for a DPFE switch or connector that is not sending the correct signal the PCM expects. The 1288 code is for a temperature sensor which may be showing a higher cylinder head temperature due to low coolant levels, blockage of water flow or bad thermostat.
The DPFE gives readings of the mix of exhaust gas returning into the intake manifold to be burned again to lower emissions.
The combination of these 2 codes can mean that too much exhaust gas is too frequently going into the intake manifold and is overheating the cylinder head causing the 1288 code. So fixing the DPFE may eliminate this secondary error which may reset itself after the first problem is fixed.
Answers & Comments
The 1401 code is for a DPFE switch or connector that is not sending the correct signal the PCM expects. The 1288 code is for a temperature sensor which may be showing a higher cylinder head temperature due to low coolant levels, blockage of water flow or bad thermostat.
The DPFE gives readings of the mix of exhaust gas returning into the intake manifold to be burned again to lower emissions.
The combination of these 2 codes can mean that too much exhaust gas is too frequently going into the intake manifold and is overheating the cylinder head causing the 1288 code. So fixing the DPFE may eliminate this secondary error which may reset itself after the first problem is fixed.