Egt ?

[mcdoobz]

Hi....when my car is cold it will run fine. But say ive been driving it in traffic in this weather (hot) my car will missfire when i put my foot down and it boost..only does this when cars hot...code read it and these codes came up...
17863
16685
16687
17864
Any help would gr8...tia

 

[desertstorm]

From the Ross Tech Wiki.

17863/P1455 - Exhaust Gas Temp Sensor 1 (G235): Implausible Signal
Possible Symptoms

• Malfunction Indicator Light (MIL) ON

Possible Causes

• Fuse(s) faulty
• Wiring and/or Connector(s) from/to Exhaust Gas Temp Sensor 1 (G235) faulty
• Exhaust Gas Temp Sensor 1 (G235) faulty

Possible Solutions

• Check Fuse(s)
• Check Wiring and/or Connector(s) from/to Exhaust Gas Temp Sensor 1 (G235)
• Check/Replace Exhaust Gas Temp Sensor 1 (G235)
  
  
  
  16685/P0301/000769 - Cylinder 1 Misfire Detected
  Possible Causes
  • Ignition system
  • Fuel injectors
  • Fuel pressure
  • Running out of fuel
  • EVAP canister purge valve
  • Evaporative emission system
  • Low compression
  • Base engine problems
  • Controle Module damaged
    
    
    
    
  16687/P0303/000771 - Cylinder 3 Misfire Detected
  Possible Causes
  • Ignition system
  • Fuel injectors
  • Fuel pressure
  • Running out of fuel
  • EVAP canister purge valve
  • Evaporative emission system
  • Low compression
  • Base engine problems
  • Controle Module damaged
    
    
    
  16687/P0303/000771 - Cylinder 3 Misfire Detected
  Possible Causes
  • Ignition system
  • Fuel injectors
  • Fuel pressure
  • Running out of fuel
  • EVAP canister purge valve
  • Evaporative emission system
  • Low compression
  • Base engine problems
  • Controle Module damaged
    
    
    
    
  
  

 

[desertstorm]

17864 is another EGT fault code related to the EGT sensor G235. Plugs and coil packs are where I would start I think.
If unburnt fuel is finding it's way into the exhaust and burning in there this will give you high EGT's , So cure the misfire and the EGT faults may disappear to.

 

[<tuffty/>]

Implausible signal on the EGT sensor is a sign the sensor is failing... a faulty EGT sensor will over fuel as it will be in permenant EGT protection running 0.75 lambda...

17864 is the excessive EGT temp fault which means the EGT have been 'measured' at being 1100 degrees (or there abouts as I can't remember the exact value without looking in the map) which I suspect is unlikely due to the other fault you have... the default value for when the EGT sensor goes south is this... you can check by logging block 112 and seeing what value EGT is...

This is probably whats causing the misfires as it running rich...

<tuffty/>