Hi All -
This forum has been a great source of info... For my 89 4runner (22re), we have this issue of strong exhaust fumes coming into the cab - for months - no visible fumes.
Haven't found the real problem yet - and today I even took it to Toyota (gulp) to see if they could diagnose, but they weren't very helpful.
She runs fine, the only thing I really notice, except for the famous sewing machine ramble is it's a bit of a dog (not a greyhound) going up some hills, need to drop it to 2nd many times.
Bottom line: Not a manifold or exhaust problem, engine compression came back at 160 - which I understand is good.
Tune up was about 10k miles ago...I was told that we need head gaskets which is the next thing on my list.

Looking for ideas on that exhaust smell ... and many thanks as always ...D&D

 

How is the tailpipe exiting?? And yes the RE is a dog but a reliable one

 

Looks normal - toyota dealer said exhaust and manifold were fine...they told me it's running "rich" which could point to different problems (catalytic converter, AFM, TPS o2 sensor) - so I thought I'd replace all of them since I've had the rig for 15 years and haven't changed any of those

 

Those possibilities suggested by the dealer sound like random ideas tossed out without performing an actual diagnosis. I wouldn't replace any of those parts without testing. Especially the converter. If you have the oem converter do not get rid of that. If you're running rich I can almost guarantee you the converter is not involved. if your converter is fuel-saturated to the point of not being effective than something upstream fouled it. Often, once the main issue is corrected the oem converter can clean itself up. If the vehicle is running rich and you replace the converter with an aftermarket one, like magnaflow, the excess fuel will quickly destroy the inside of the converter, and their warranty specifically omits this type of damage from warranty coverage.

If your cap/rotor, and wire set are something other than Denso than replacing those wouldn't be a bad idea. Toyota sparkplug wire set are better quality and durability than Denso, but are pricey.
I'd install a set of regular resistor plugs, ND or NGK. Don't bother with platinum or iridium. I prefer the ones with the solid terminals that don't unscrew. Definitely do not get Bosch sparkplugs.
Make sure timing is correct, than set TPS using the timing light method described in Sticky Section.
Once you done all this get a manual emissions test with a read out. Now you'll have some data to work with.

 

if you are driving with the rear window cracked open it'll suck fumes into the cab, very annoying... the next gen of 4runner got a little scoop on the roof, i wonder if that is what it's for.

the factory manifold exhaust gasket at the head is weak sauce to begin with, and that's being nice... if the manifold is warped it's probably leaking... easy to diagnose with a flashlight, or get out there when the engine has been sitting all night and briefly hold your fingers at the manifold to head junction while someone starts the engine, if it's leaking you'll feel it... same thing with the manifold to pipe joint.

the solution is a remflex gasket, i've been running one for at least 10 years now, including removing the engine a couple of times.