Driveabilty issues

[migii]

I have been trying figure out an issue while driving my 1997 LX450 330,000 mile , while driving foot on gas it starts
to have this sonic feeling vibration and slight missing on incline ,what I have done so far

1. changed tranny fluid,it was clean no metal
2. checked wheel bearings, ujoints diff fluid , all good
3. changed motor oil and cut open filter, all clean
4.Cap, wires ,plugs new OEM
5. No codes present all readiness monitors ok

now I have taken the intake manifold off and found a completely clogged EGR port in the top of the manifold.
I cleaned it all out but have not put it back together I'm going to clean the injectors while in there.
So the question I have is would that clogged EGR port cause my issue or would it be injectors or other?

 

[Rusty Marlin]

Does it miss when romping on the gas to get on the highway?
Just wondering if its a "load" sensitive issue.

Does NC have smog checks? If not, while you have the intake off is a great time to delete the EGR.

 

[migii]

Does it miss when romping on the gas to get on the highway?
Just wondering if its a "load" sensitive issue.

Does NC have smog checks? If not, while you have the intake off is a great time to delete the EGR.

No miss at all when getting on highway, but while cruising and flooring it, it will not get past 80mph and it's slow to get there.

No smog for me.

 

[Rusty Marlin]

Fuel filter? Seems like a cop out answer, but not sure what else.

 

[PeterTheBeater]

Check your O2 sensors, I had similar issues

 

[migii]

Fuel filter? Seems like a cop out answer, but not sure what else.

New OEM FILTER new OEM fuel pump

 

[migii]

Check your O2 sensors, I had similar issues

NEW Denso O2

 

[leonard_nemoy]

Have you checked your intake tube for cracks?

 

[PeterTheBeater]

NEW Denso O2

Up stream and down stream? My downstream bosch went bad and i replaced it with denso as well.

 

[migii]

Up stream and down stream? My downstream bosch went bad and i replaced it with denso as well.

Yes both are new

 

[migii]

Have you checked your intake tube for cracks?

yes , I replaced it but no change in symptoms.

 

[leonard_nemoy]

Check all your vacuum lines. You can carefully spray starter fluid at different vacuum lines or different areas in the engine bay with the motor running. Than you can either listen for a change in idle or better yet if you have an OB2 rig, hook up a nice scan tool and watch for a change in rpm's or other PID's as you spray the starter fluid in small safe amounts.

This can be a great way to find a vacuum leak or unmetered air entering the engine. You can also do this while giving it throttle with the engine under load.

 

[leonard_nemoy]

Also if you have had your injectors unplugged recently make the sure the injector harness plugs are hooked up correctly. This is a quick easy visual. The plugs are two different colors and the colors should be alternating. Brown and I forget the other color off the top of my head.

And don't forget to check the wiring harness by the EGR

 

[migii]

OK I got everything back together cranked and running, but now have P0301 P0303 P0300 truly running like crap, checked the wire harness by the egr
and glove box and it "LOOKS" fine. I have had it wrapped in more protective heat layers since I have owned it the past 7 years. injectors all ohm out to spec
they are all clicking maybe a deeper look into the harness? this is my baby and I want to fix it anymore ideas gentlemen?