How's it goin Fellas!
So I am new to this forum as well as the 4runner world. I have always liked 4runners but just recently got rid of my tundra and picked one up. So far so good! Im driving a 1997 SR5 3.4 4x4 with 116k on it, 3rd owner. The service documentation was decent but no real details. My goal is to have my runner as a DD as well as be able to go mild off roading and take it up to the snow every so often. First of all I want to upgrade the performance and get the maintenance down then later work on the lift and tires etc. What are some inexpensive suggestions to help with the performance as well as longevity of my runner? Also, unfortunately I live in the Bay Area of the great state of CA and you all know how lax our smog regulations are.......... It's gotta pass smog. Not to mention I just recently had my cat hacked off so any suggestions for that situation would be helpful too! Thanks for all the ideas guys and I'm looking forward to a fun future with you guys and my runner! Excellent Forum!!

Short of supercharging it, no real performance mods out there that are really worth the money. Search "deck plate mod" and "ISR mod" if you want a little better sound though.

Good luck with it and welcome.

Sorry to hear about your cats getting ripped off. Unfortunately you will be CARB approved cats assuming your 4runner is a California vehicle. If it's an out-of-state vehicle you might be able to get away with a 49 state cat. From my understanding it's not technically legal to buy used cat's, so your options are going to be limited. Might want to check out summitracing.com their shipping was super cheap.

After you get a new cat you might want to look into some under armor (not the clothing line). Makes it harder for thieves to get to your cat.

Supercharging it is a little too expensive for me right now although I would like to do that in the future. Would the deck plate mod and ISR mod still make it pass smog?

Get yourself a tranny cooler if it's an auto, you dont wanna risk the milkshake happening to you. Also check the ball joints and tie rods, they tend to fail faster than other things on 3rd gens. Good luck with the cat issue, the bay area is really getting hit hard with cat theives

And yes I am in CA so I am limited in my replacement options for my Cat. As far as Cat theft prevention goes, has anyone ever used/heard of a "Cat Clamp"? What is my best options for theft prevention?

Definitely do all your maintenance first, before any mods.

Search here for threads on this. I remember a thread talking some details about non-OEM cats that are CARB approved (I think there was at least one). Someone here was talking to the emissions office or whoever runs that and was getting some good info on CAT's in Cali

Deckplate and ISR will not help you pass inspection. IMO don't bother with either right now. If you really want to do something, do the ISR. I know alot of guys run the deckplate mod, but do your research on it here and on yotatech; there is a good chance that it is mostly a placebo effect mod.

There is a good thread over on yotatech that actually gets technical about the benefits of the deckplate mod (dyno runs, and some basic fluid mechanics).

I agree with these (though I wouldn't do the tranny cooler first). Also:

Spark Plugs
Spark Plug Wires
seafoam cleaning treatment
diff breather extension
change gear oil in front and rear diffs and transfer case
Flush/bleed brakes (and check the pads)
Tranny flush and fluid replacement.
Power steering fluid replacement

Spark plugs and gear oil I think should be at the top of your list as they are most likely to be bad, or to not have been replaced regularly.

Thanks for all the great info. I am definitely gonna look into a few of those options. And yes it is automatic so i was leaning towards the tranny cooler pretty soon. Nelsonmd when you say the mods wont "help" it pass inspection are you saying if it wont pass now its not goin to help it pass? Or are you saying if youre looking to have it pass those mods might prevent it? It passes just fine now and I would like to keep it that way. Thanks for all the input guys!

If it is passing now, I wouldn't touch the intake. You will get some arguments from guys that say the deckplate/ISR gave them performance improvements, but it is in question whether it is a "real" gain, or placebo. Not saying it WON'T give an improvement, but you are changing the stock setup that the engine and components are tuned to, so I need to see some real data before believing that it is better. I would also question that you could improve your emissions through these mods because any minor mod like that that would improve emissions would probably be exploited by Toyota to help them meet the strict requirements they have to meet.

I can't say that it deckplate will cause you to fail if you are borderline, but I haven't heard that it helps either.

You will get FAR more gains from doing the maintenance items then by doing either the deckplate or ISR. I am mostly trying to encourage you to shelve those mods until you get all the maintenance done, because that is way more important than increasing intake flow (I think the exhaust is the bottleneck anyway, not the intake)

Excellent knowledge! Thank you for all the help. I am definitley gonna work on the maintenance before any mods. So after I get all the maintenance down rather then going with the deck plate mod, would you recommend putting a k & n CAI in? What's your take on that? And suggestions for exaust?

An afe reusable/washable drop-in filter is better than the K&N in my opinion because it makes it Idiot Proof, it takes all the guess work out of knowing how to oil/reoil your filter so it(The oil residue) won't clog your sensor.

One good thing about the deckplate mod is that when you take it to get inspected, you can just screw the cap back on and its like it was never there...

I personally don't recommend any intake mods unless it's a supercharger. If you can tune your engine, then you might be able to take advantage of a CAI, but if you can do that, then I don't think you would ask the question. I seem to remember people saying that a CAI made it not run as well as stock. There are some more technical discussions over on yotatech you can search for.

For exhaust, again, don't bother, stock is fine. Now that I think about it, the stock exhaust can handle the supercharger, so maybe it isn't the bottleneck

Either way, if you really want a performance mod, start looking into a supercharger with 7th injector. It is made for this engine, and will give you real measured gains, not just a bunch of un-scientific opinions from us random joe blow's on the internet.

Or you could just use a disposable one. Even more idiot proof as long as you replace it regularly.

And the bad thing is that it may not do anything for you but put a big hole in your airbox. I think way too much emphasis is put on this mod just because it is cheap and easy, but I think the benefits are very nebulous...