P073B Diagnostic Trouble Code

P073B is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a P073B diagnostic trouble code may include:

Poor acceleration
Cherry red hot catalytic converter
Possible spark knock (detonation / pre-ignition)
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

An air leak forward of the DPF will change the sensor readings resulting in the code
Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.

Repair Processes :

If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. If the engine displays a miss and there wasn't a code, determine which cylinder is misfiring. If the exhaust manifold is visible, spay or pour a small amount of water on each cylinder exhaust port. Water will evaporate immediately on good cylinders and slowly on the missing cylinder. If this can't be accomplished pull the plugs and check the condition.

Process Tips

Diagnostic trouble code P073B is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before P073B.

Fortunately, P073B is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P073B Trouble Code For Specific Cars

P073B Rover P5 Ignition Control (IC) Circuit Low Voltage
P073B Treser Roadster Passenger Side Crash Sensor Communication Fault (Non SCP)
P073B Buick Roadmaster Cylinder Head Temp Sensor Out Of Self Test Range
P073B Skoda 110 IPR Circuit Failure
P073B Gaz 29 O2 Sensor Circuit Malfunction (Bank 1 Sensor 3)
P073B Fiat V8 Left Lamp Outage Signal Circuit Short to Ground
P073B Mazda Washu A/C Post Heater Sensor #2 Circuit Failure