Sr5 4cyl wrong cat causing power loss

New here so bear with me.

I purchased my 2016 SR5 Tacoma last year, the 2nd day I had it the check engine light came on saying it was the catalytic converters. The dealership was willing to replace them so they did. When I got the truck it felt slightly better. I’ve always noticed a weird powerloss in the truck. After a few weeks I looked into it and found that they didn’t replace my cats with OE parts, which had 2 cats on one pipe, they just cut out the cats and welded a single cat. I’ve heard things about backpressure being of importance for these trucks and I want to make sure it’ll help with a slight boost in performance if I put the OE cats in. No this wasn’t a Toyota dealership

 

welcome

how do you know there is a power loss after one day of driving? The 4 cylinder in this heavy, un aerodynamic truck isn't know for for performance.
If the exhaust is restricted, yes it could cause a loss in power. Not sure what you can legally do about it though, you might have to replace on your own dime, and unfortunately have to buy it to try.

 

Sounds like they went the alternate route with the install.
Any good welding shops where you are?
If you did free up the exhaust by removing the back pressure, then your engine should be able to spool up faster through the RPMS.
Might have more power but less torque (as both are a trade off with one another).

 

Have you driven one that hasn’t been touched to see if it really is the catalytic converter or the truck just being slow?

 

I can't imagine deleting a cat would cause the truck to run slower, especially if one or both of them were clogged. That said I will always choose a high flow cat when given the opportunity.

These trucks aren't that powerful to begin with though, esp in the 4cyl version. You might just be feeling 'the truck'.

 

i too am doubting what you said. 2.7 comes with two cats, one cat would be enough backpressure, the second cat is there only to catch particles when the first cat is cold. you would maybe lose backpressure but enough to make you notice a big difference is a big maybe. I'll be deleting my second cat soon so I'll will find out myself soon enough, maybe youre right.

 

Is the truck mileage beyond emissions warranty? Not that Toyota would do anything now that it's been cobbled, but it would be consideration for others who might read this thread with similar problem.

I will say cats do fail. But not super common. Often there is an upstream operational problem that causes the failure.

Will the new setup pass inspection in your state?

 

Back pressure creating more low end tq is a myth. Back pressure does nothing but hurt performance at any RPM range.

 

Never found that to be so. You need a certain amount of back pressure. I recall losing some low end torque in my 4.7 tundra when I went to a dual exhaust system starting with flow master cats and going back vs the stock single. With the flow master system the truck made more power up top, but hurt drivability at low speeds when towing, vs the stock exhaust.

 

I’m confused by your post … in the first part of your post you said “dealership”. What dealership was willing to butcher your car ? And did they tell you what type of work they are doing ?

 

That's not back pressure losing the low end power; it's exhaust velocity.

 

ive been deep diving into this subject for the past couple weeks and I cant get a straight answer. I dont really have any real life exhaust expert I could talk to either. I hope youre right but man there is so many people saying the opposite too. I hope someone like Tinkerer's Adventure could do a video on.

 

https://www.youtube.com/watch?v=_PVXvHkr-Vs

 

Well it all comes under scavenging imo.

 

Smaller diameter pipe means the exhaust gases flow quicker. Less in a shorter amounter of time compared to a wider exhaust. The engine pulse adapt to whatever is installed over time. Engines are basically air pumps.

 

I went to Bosco Autogroup. It’s in Texas, I don’t recall exactly where but I know North West of Dallas. Been a while sorry.
Anyways, left some pretty nasty reviews. Buddy of mine thinks they may have added a throw in cheap $100 catalytic converter they use on racing cars. Just so they “have”something on them. I really don’t know. Just a crap situation.

 

Ive come to terms with fixing the issues on my dime. This abandoned hunk of steel is officially mine and I’m willing to do everything in my power to give it a full, capable life. I’ve given her a tune up, brakes, rotors, shoes, drums, billstein struts, battery….. subwoofer

I just want the performance to be what is expected. But I may drive another 4 cyl to see if it’s comparable. It just doesn’t sound very good either. Like if something on the exhaust is off. Idk. I know I’ve heard enough vehicles to know something is off.

 

let me know brother.

 

I’m not saying it doesn’t, but talk to someone and see if it even passes your state’s requirements, many states force dealers to make sure a vehicle sold by them, properly passes their smog regulations.

 

If the single cat flows the same cfm as the dual cat setup, I don't think that would be an issue. What may be an issue is that the oxygen sensor may not be in the correct location in relation to the different cat setup, and now not sending accurate readings. Just a guess on my part. Heard about this somewhere in the past, don't remember now exactly.