pinging extremely bad

[bigshoes865]

99 4 cyl. pings bad after warm up. mostley driving down interstate.will rattle so bad i will slow down or change gears,mashed to floor or just part throttle. still does it. i changed dpfe, cleaned egr ports, and vacume checked, new mass air flow,checked fuel pressure.new wires plugs,filters.checked timing marks.ran sea foam and other brands. i do not know if truck had issue before i bought in winter of 2011. not so noticable while in winter months. higher octate does almost elimanate pinging.170k miles. this is how bad it . i work 3 min off interstate. runs perfect for 8 min of drive time after i leave work on interstate then starts to ping on light throttle, and gets real on light grade. at highway speed. 60or 70 mph. any ideas?

 

[Mark_88]

Check for codes...maybe put some injector cleaner in the gas tank...shift sooner than later...keep revs low if you can...

Sounds like you're getting a lean condition or your engine is running too hot...and it may be caused by crud in the injectors...could also be you need to check/change the thermostat...but find out if it is throwing codes and go from there...

 

[bigshoes865]

problem solved

after pulling all my hair out . i used my brain.so i ran vacume to a tee on egr valve and drove. vacume to egr worked fine for a few miles. as soon as it warmed up it it lost vacume. heat related. got up next morning for work. egr worked again ,few min. checked codes at work . none. ran voltage to sol. valve when hot . it worked. tried a new dpfe from shelf. drove it three day valve still works hot or warm. pinging has stopped. i had change so many parts i thought i tried a dpfe,but did not. with no codes somtimes it is guess.

 

[RonD]

So another DPFE fixed the pinging.

Thanks for posting the fix