For the first minute or so of running it's fine but after it warms up it bogs out and dies when throttle is suddenly applied. It's an s5 na. If I ease very lightly into the throttle ot revs up but tries to die when rpms fall. The engine codes I get are 12 and 51. So I've narrowed it down to tps or fuel pump relay. Any advice?

 

fix the codes first. i would clear them, and adjust the TPS, and see what it does. if the ECU thinks it doesn't have fuel, it will limit your power

 

Thank you for giving me a good starting point.

 

Check to see if coolant temp sensor is within spec or just replace it and the coolant. Coolant temp sensor is a variable resistor which affects fuel mapping.

can check the sensor by monitoring resistance via multimeter while varying coolant temps in hot/boiling water.

Do a visual and vacuum leak test and check what has been mentioned above.

slowly sweep the tps and check resistance to make sure there aren’t any open circuits.

 

Thanks! I'll try that in the morning after I get home from work and see if I can find the issue.