Custom Exhaust System
The exhaust system is one of the biggest bang for the buck modifications that can be made
to the 22R/22RE engine for moderate power gains.   This page described the route I took
and the parts I used.
When choosing to modify the exhaust system, one of the biggest concerns to many people is how it will
affect emissions control certification.   In general, modifications can be made after the catalytic converter
with no affect on the vehicle's emissions control system.  This means modifying or removing the muffler
and the piping between the catalytic converter and the muffler and the piping after the muffler.   While
many companies make and sell these "after cat" or "cat-back" systems, in general, the gains they allow
are nominal.  In addition, they can be extremely expensive.  It's commonly thought that the stock system
is very restrictive, but it's a debatable point.  In general, the affects of a modified exhaust can offer slight
gain, to no gain to an actual loss in power, depending on how it's done.

Some of the biggest exhaust related power gains can be made my adding a header and a higher flowing
catalytic converter.   For my system, I choose a high quality header from LC Engineering and to make up
for the cost, went with a  new aftermarket higher flowing catalytic converter and a custom cat-back pipe
and muffler.   The LCE header uses 2.25" pipe collector pipe.  I ran 2.25 pipe to a 2.25" in/out cat
converter and then ran 2.25" pipe to a Flowmaster 50 series.  From there, the exhaust exits out the rear
of the truck via 2.5" pipe.    To address emissions concerns, the LC Engineering header is completely
emissions legal in at least California and has a CARB exeption.

It's difficult to tell how much gain in power I might have noticed because the excessive weight my truck
carries, but I think the increase is significant.  My truck is by no means fast, but it feels a lot better than a
100 h.p. motor with 200,000 miles pulling a 5000lbs truck should feel.
The LC Engineering header.  Install and fit
was easy and flawless, except for one thing.
That darn emissions piping was a bear to
take apart, thanks to it's stud flange mount.  
Otherwise the header fit great and came with
a nice factory Toyota gasket.

My header apparently was one of the last
ceramic coated units.  New LC headers are
304 stainless steel, and for the same price no
less.  I wish I would have waited.

The most important trick with install is to
soak those exhaust manifold bolts with lots
and lots of penetrating oil and days or even
weeks in advanced.  You can't use too much.
.
This image shows the supplied LC engineering
downpipe which included plumbing for the 02
sensor.  Some models have the 02 sensor in
the header itself.
Catalytic converter and muffler
This image shows the custom aftermarket
high flow converter, custom piping and
muffler.  I chose to go cheap on this end
and have it all custom made.  LC
Engineering does sell this entire exhaust
section but at a higher price than it cost me
to have a local shop build it.
I chose to have the exhaust end here for a
number reasons.  Cost, simplicity, and to
reduce exhaust restriction for power.  In
addition, I was able to have it custom built to
retain as much clearance as possible.

However, it became clear I would be wise to
extend the exhaust out to the rear.
I initially went with a Flowmaster 40 series
muffler, but that proved too loud for my
taste.  Especially at speed.  But did give the
very unexpected sound of a V-8 rumble at
idle.  I had more than one person ask if I had
a V-8 in my truck.   I later upgraded to a
larger Flowmaster 50 series, which you see
pictured here.  Quieter sound with no
noticeable loss in power.
This is the custom rear exhaust pipe.  Exits at
near the stock location, but designed for more
clearance around the spring.  The pipe from
the muffler back is 2.5"
SUMMARY

I'm basicly happy with the set up.  The power gains were definately noticable, although the majority of it in
the upper rpm range.  I do not feel that I lost any torque output, even at the lower rpms.   I would highly
recommend the LC Engineering header.  Especially now that they are making them in stainless steel at
the same price.  As for the rest of the exhaust, LC does make a good kit, but I still feel custom is more
cost effective.  As for sound, it's a bit loud.  I would like to make it a bit quieter, but I also hate to lose any
power in the process.
Links to other exhaust info