Would these exhaust leaks cause my trucks RPMs to go from 550-650 after warm up?

I have been trying to find a small shake for the past two years. I changed almost everything. Cleaned the IACV (not that dirty), cleaned the MAF, changed all the hoses, changed out the fuel injectors to Motorwest, changed out valve cover gaskets and o-rings, both o2 sensors with OEM, OEM spark plugs, coils, and wires. I smoked it and no leaks. However I do have a small knock/tapping sound. Used a mechanic stethoscope and it was clear that it was coming from the exhaust pipe right by the exhaust manifold on the drivers side. Did a vacuum/soap water test and I found a handful of spots leaking. Would this cause rpms to go up and down a bit? It’s not horrible but it is very annoying. My father in law has a 2000 Tacoma with the same engine (5vzfe). Lower miles but no shakes at all. Mines a 95 with 232k on the clock. I finally got check engine light p0420 but I erase it and it comes back maybe once every 2 weeks. Thoughts?

 

I was going to say just install some new flange gaskets, but then I saw that its impossible. You might need to replace the header and midpipe.

 

yeah, dont touch those bolts...............
Dont think those will come out, maybe getting them glowing red hot with a torch but you need to deal with the broken one...

Looking at it again, a guy with experience & a real torch may have a chance....
Rattling from an impact is your friend, hand tools & its over....

 

A few concerns from the pic, the wire between the exhaust man & steering shaft, is that suppose to be there?
Also the cable with the heat conduit around it, is that out of position?
Im not a toyota tech, just observant & im questioning those....

 

yeah it’s pretty brutal. At this point I think I’ll live with the little shimmy. It’s not bad just annoying.

 

O2 sensors and A/F sensors are hyper sensitive to ANY false air. On my 96 I found the power steering vacuum switch valve to be the culprit. Another false air spot is the seal behind the master cylinder, not the paper seal, the seal on the snout of the master cylinder. How tight/loose is the throttle shaft in the bore of the throttle body and how clean is it?

 

your right on track......

 

interesting. I have a very leaky rack and pinion that is soon to be replaced. I’ll look around and consider the vacuum switch. As far as the master cylinder I noticed that it’s fairly new. Wasn’t told it was replaced. Is there a way to test if the gasket is bad? Spray carb cleaner around it?

 

is it this?

 

im not exactly sure what you mean by the throttle shaft in the bore. I cleaned out the throttle body and IACV

 

I had leaky exhaust gaskets- I was able to separate the flanges and put new ones in. It's a pain.. but your studs don't look impossible. My truck was in the garage for a few weeks while I did a complete front end refresh, and I did the exhaust last. I hit the bolts with pr blaster for a week before even trying to get them off. pb blaster, and a gently taping on them with a hammer (or some extension and a hammer).. I was ready with new studs for when I broke them, but to my surprise, the pb blaster worked it's magic, and I was able to get them all off. That being said, you need a lot of random extensions and universal joints to get at all of them. So it's not impossible.

 

PB FTW!

works really well......ESPECIALLY if you start applying several days b4 like Andy01 states

 

thank you. I just realized some of the pipes don’t even have nuts anymore. Lol. Just hanging by a rusty stud.

 

Awesome You're saving time from having to get those ones off. The studs thread into the flange, so the pb blaster + tapping method still applies, but it's just gonna be a whole lot harder to get 'em with vise grips. If they have thread on them, you might be able to thread two bolts on tightened against each other, and twist the stud out...

The other helpful hint, make sure you're using a 6 sided socket or a crows foot wrench on the nuts that are still there.

 

It's great but the stank makes me want to barf. Good stuff, but I hate it.

 

I got a PB air freshener I got for you madnachos!!!!

 

The old tri-flow spray smelled like bananas

 

Those exhaust leaks will definitely cause your truck to run rich but I doubt that it would be causing RPM fluctuation or shaking. Those leaks make your O2 sensor see a lean condition and your ECU will start dumping extra fuel. You likely getting the P0420 because your catalytic converter cant burn off the extra fuel. That is strange that your truck starts off at such a low RPM and then climbs when it's warmed up. Can you read coolant temps with your scanner?

 

Ha! Love it. Good luck on a hot summer day hehe.

 

Totally. I remember. And frankly that stuff was epic. Game changer.