F150 gas tank swap/CA smog compliant?
 

Ok I have beat the snot out of my factory gas tank after a couple trips on the Rubicon and other trails. I remember reading about guys doing the F150 gas tank swap to get the tank out from in front of the rear axle.

I'm sorry if this question has come up before, I've tried to search but haven't seen a clear answer. So is it possible to do this swap on a 1996 4runner and make it CA smog compliant, without "knowing a guy"? If not I guess I will need to replace my factory tank and get a real skid plate for it.

Ryan

It's a bit of gray area honestly. The CA smog law states that any additional or oversized fuel tanks must have a CARB approval, but the F150 tank is the same fuel capacity so it is not "oversized" and it is a relocation of the tank, not an "addition", so it should technically pass. I know many guys with this swap that pass smog with no issues. It can also depend on the smog guy as well - not many smog guys are going to look at the fuel tank or even know how the stock tank looks or where it should be (many really don't care). I think as long as it is all "stock looking" you should be fine.

OK Thanks.

As long as all evap and fuel vapor lines are intact after the swap. If they are not, it runs the risk of throwing an EVAP code.

Your average smog tech won't be able to tell the difference between the two tanks.

This right here. It is definitely illegal - but not in a way that many/most smog techs will notice.

-Charlie

Sorry, but what part of what he said are you saying is illegal?

I assume there must be a write up somewhere of an install, regarding the evap lines and everything?

It depends on the personnel more than anything. Some smog guys refuse to see ANY modification to factory stuff. Some don’t even bother and just run it; no CEL, clean tailpipe, done.

When I did my 3.4 swap in the 2nd gen 12 years ago, I took it to a Referee to get it legalized. He ran it and it literally had just about ZERO emissions: a perfectly running system. But he initially failed it becuase the exhaust had been modified prior to the catalytic converter-for those that don’t know, modifying the exhaust is MANDATORY to accomplish the swap.

Anyway I argued with him a bit, becuase it’s literally just pipes and the result was the entire goal of smog: a cleaner running engine. He eventually talked to a supervisor and passed it. Moral of the story: it depends on the person. No CEL, running and passing a pressure test on the gas tank, clean tailpipe, and you’ll be on the road for 2 years.

You could also do the swap immediately after smogging and passing so you can enjoy it for 2 years before the next smog.

Gas tank shape, size, type, location, must be stock. All Evap lines must be stock, etc. (stock or stock equivalent, I mean). That's the official word. Whether it gets noticed is a different story. They generally will be ignoring anything in the back half of the vehicle, other than the gas cap.

I've had smog techs fail (well, nearly fail) me for crankcase vent hoses that were cracked at the ends, past the sealing lip... I actually had the replacement parts in my possession so he let it go. That was on a Subaru, but you get the idea.

-Charlie

It really depends on who tests you. I passed smog yesterday :D and the person didn't even notice the mini-header swap, nor did they notice the small crack in my old manifold.

If a tech goes by the books they should fail you. It doesn't mean you cant fit aux tanks in California, but they have to be CARB compliant. Here's California's pathetic website on the matter, with some gas tanks you can use... from 1990.

I have not heard of this being a replacement. I thought you guys were doing the f150 in the spare tire area as an extra to have another tank when out in the out back to help us with our great fuel economy :)

Most people are using this as an alternative to the stock tank for better weight distribution and ground clearance. Some people also do this in order to do a rear 4 link setup. There are a few people using this as an auxiliary tank as well.

I personally wouldn't worry much about it like most folks here are saying.

I currently run an IS300 with a 1jz swap ( stock was the 2jz, but the 1jz's sound better) and a manual trans swap. My ecu is still stock automatic ecu wired to think its in neutral all the time ( basically all wiring that tells it what gear it is in is wired into the neutral). Never reffed....always pass smog. The 2 different motors essentially look the same so they don't know the difference and my ecu doesn't have any codes for them to pick up.


Doubt most folks will catch a relocated stock looking gas tank is my point.

Yeah, as mentioned, various reasons for different needs. Flat belly or new suspension geometry - probably want to get the original tank out of there. Extended range without carrying external tanks? Probably adding a tank and leaving the original. I did the latter on mine, was tired of strapping gas cans to the roof rack so I added a 16 gallon tank back there.

Ya I have some experience with how different techs/shops look at stuff. I also have an F250 with the 6.0, it's fully bulletproofed Banks system, and so on. One guy will get all weirded out just by the censors for my monitor and asking "what's this? what's that?" Just took it in for smog check to different shop but same chain, was in and out in 10 mins didn't awk one question.

So I will dive into gathering more info on doing this project. Thanks for the feed back guys.