Pulled these codes off my 90 F150 with a 5.0. The 51 seems simple enough but the code 82 seems more in depth. Engine started making noise the other day that sounds like the ball spinning on a roulette wheel. Under load the noise is more constant and louder than at idle. I had just replaced the smog pump. Could code 82 be causing the noise? Any thought would be appreciated.

 

82 is pointing towards the TAB (Thermactor Air Bypass) solenoid. Check the vac. lines running to it and from the vacuum canister it's connected to.

If the smog pump was recently replaced, loosen the serp belt from the pulley tensioner and check the pulley for the pump to see if there is any grinding or hesistation when turning or spinning it.