I just filled up with a fresh tank and will see how it goes. In the mean time, could loose DP to manifold nuts or a ticking flex cause knock?

Before I filled up today, I was able to get into the throttle fairly aggressively with little knock. It knocks the most when the TCC is locked and I push into the throttle. I'm not sure if the vibrations resonate in a certain way and cause something loose to rattle or what. The DP wasn't installed by me (had to take it to an exhaust shop and get the OEM DP cut out) so I can't be certain of their tightness.

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

I wouldnt think that could cause knock...definetly not that much. no way. If it knocks when the tcc is locked it is either because of TM or because the engine is in a high gear and high load. wich could be normal. Shoot if i remember correctly i think the TM settings in dhp for the tcc locked are called something like ''Max torque TCC locked'' ''Max torque TCC unclocked' or something of that nature. Good luck and let us know

__________________
1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~#4 FMHE~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~ZZP SS Headers~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's

I guess it is real knock then.

Why doesn't it knock when I get into the throttle more and the TCC isn't locked? Like somewhat aggressive acceleration in 2nd gear around town...

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

Well think about it like this. There is more of a load on the engine because of the tcc being locked and nothing beng allowed to slip. And that is why the knock is occuring while the tcc is locked vs. when it is unlocked. Plus like i said there is a TM table for it also. I guess if that doesent make since it's almost like being in forth gear going 30 and flooring it...lot's of excess fuel,big load on engine ect.

__________________
1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~#4 FMHE~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~ZZP SS Headers~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's

Meant to say that I have those TCC tables filled to the max so they should never try to limit me. It's weird that I can get into the throttle and not see hardly any KR (nless I hit PE, that's still f'd up) but I can barely cruise without seeing 1.5-3*.

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

Did ya get anything figured out yet man?

__________________
1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~#4 FMHE~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~ZZP SS Headers~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's

Been on new gas for a couple days and no change. I'm also pretty sure it's real knock because when the engine is still pretty cool it won't do it. So, something is heating up in there and causing knock.

I've got nearly 68k miles on the factory iridium plugs and I think they're causing knock. New plugs are on the way, and PRJ wires will meet me back home later this week. Tuesday I'm changing my O2 sensor.

So, I'll see what happens. I've successfully eliminated gas as the issue, though I'd hate to see how bad it is with 87 instead of the 91/93 I have been using...

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

No luck with changing plugs, O2 sensor, and wires. I'm now on AL605s, PRJ wires, and a brand new AC Delco O2 sensor and it's still the same, if not worse.

I went WOT once and saw a solid 8* of KR with 880-890 O2s.

Is the MAF used during WOT or when in PE? It might be suspect. I'm going to unplug it and see if the car acts any better...

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

Also, would a leaking o-ring on an injector cause some knock? I smelled a little fuel while leaning over the alternator, and looking at the jetting on my #2 plug it may show some lean running. If I had a vacuum leak at the o-ring for that cylinder's injector, it may be explained.

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

Yeah the maf is used all of the time. If you unplug it the pcm is going to resort to the VE table. How are you tuning your fuel? VE Table? Injectors table? MAF? Lets say you were tuning the fuel on your car by the maf. You got it running right. then you unplugged the maf. Well then the pcm is going to be looking at the VE table. Wich has stock fueling...get it? the VE table never changes unless you change it. It's been up in the air but some people claim that there car doesent even use the VE table with the MAF unplugged.

Some people are able to zero out their VE table unplug the MAF and there car will run just fine. Me personally I dont tune the fuel with the VE table. I just use the MAF. And also some people say the only reason the ve table is even there is in the even you have a MAF falure, your car will still run. But if you dont tune via the VE table and you are highly modded and you happen to have a maf failure then your car may not run anyway lol.Some people also say that its better not to tune by the ve table and some say it is. just a matter of opinion i guess.

__________________
1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~#4 FMHE~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~ZZP SS Headers~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's