Can’t figure out Misfire Issues

Hybee

Member
I have a 2003 Tacoma with the 5vz-fe v6 with 175k on it. Threw multiple misfire and cylinder 3 and 5 misfire codes. I had just purchased the truck so I replaced all spark plugs(Denso), ignition coils(Denso), ignition wires(Denso), cleaned MAF sensor and throttle body, and installed new air filter. Check engine light came on about 200 miles later with the same codes. I then proceeded to replace cylinders 3 and 5 fuel injectors. Check engine light just came back with the same codes. I’m not experiencing any loss of power or hesitation through acceleration that I can tell. Has a shake at idle but goes away when given some fuel. Vacuum lines seem fine. I’m about out of ideas. Any advice would be appreciated.
 
Seen a discussion about this same subject in a different forum. Some was agreeing over there that it could be cam position sensor, especially with both codes being on same bank. I'm no authority on this, just relaying what I've read.

I don’t think it would be cam positioning sensor because it is not throwing a code for it and I’m also not expiriencing the symptoms of this issue from what I could tell after looking them up. Thanks for the info though. I’m trying to rule out as much as I can before breaking down and taking it somewhere.
 
Maybe try a compression test?
I think I’m going to have to! I thought about that after I replaced the injectors but I figured if I was losing compression I would be able to feel a loss of power but there’s none that I can tell. Only noticeable thing is a shake at idle, which, from what I’ve read, is common.
 
I think I’m going to have to! I thought about that after I replaced the injectors but I figured if I was losing compression I would be able to feel a loss of power but there’s none that I can tell. Only noticeable thing is a shake at idle, which, from what I’ve read, is common.
A shake at idle with 175k miles is NOT common
 
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