Help pinging noise and throwing code

[Blackone51]

My 1998 gt has this pinging or clicking noise after it warms up and only under load, it's fine at idle or if I really get on it. I thought it in the accessories cause it wasn't pinging or clicking with the belt off, so I changed the alternator, idler, belt tensioner, and finally the harmonic balancer but found out it still did it with the belt off when it was warmed up. I was wondering if it could be detonation or spark knock? What does that code mean? Or am I just screwed and have to skip painting my car over the winter and get a forged bottom end?

Please Help this is really frustrating me, if my engine is screwed at least I know and can start the forged bottom end process.

 

[Blackone51]

I guess P1401 is differential pressure feedback electronic sensor circuit high voltage. I did a little research and this is basically saying the egr valve is staying open to long. Could this be causing my pinging or clicking noise under load? Could the egr valve staying open to long cause detonation by running lean? THanks

 

[Blackone51]

Anyone else experience detonation because of their EGR system was not working properly?

 

[Flghtmstr1]

An EGR malfunction can cause detonation.

 

[Blackone51]

An EGR malfunction can cause detonation.

I am just trying to figure out if it is detonation. It doesn't do it till the car is warmed up a little bit and it gets worse the longer I drive it but never does it at idle just under load. I also unpluged the MAF and drove around, the pinging/clicking was a lot quieter but still there. Does this sound like it is detonating or is it the start of a bad rod etc...? Please help!!!