Aftermarket or OEM catalytic converter and O2 sensors?

I'm hearing too many people say that the aftermarket cats don't last long. Or that the aftermarket cats are not meant to be on the Tacoma, so if you have a check engine light on then putting an aftermarket cat won't clear it because the sensors or electronic system won't match it correctly.

The price difference is what makes me second guess what I should do. What I want is a product that will last and do the job. So if that means spending more on an OEM cat then I'm fine with that. Just thought I'd ask for the opinion and experience from others.

Also, if I go with an OEM cat, am I able to just switch it out or should I take it to a muffler shop?

Last question... Is there 1 or 2 cats on a 2001 3.4L Tacoma. I've been told there are 2, but also reading other people posts about how their truck is under California emissions so they have 2 cats. I'm in Austin, Texas so I'm not sure if mine should have 1 or 2. I took a look the other day and it looked like there were 2 cats. But then I looked online at Toyota.com and the diagram on their website said the 3.4 only has 1 cat. So I'm kind confused as to how many cats my truck has and actually needs to have in order to pass emmissions testing here in Austin.

Thanks for y'all's help!!!!!!!

 

Just ran into this problem. I did a lot of research! I went with the magnaflow oe highflow cat. I ordered it from summitracing, $328 shipped for the front cat. It fit wonderfully and I have 0 issues. As for sensors, I went oe. hope this helps a little!

 

Did u check your o2s yet? Its pretty unlikely the catalytics are bad.

 

I have 2 cats, they are fine at 180k and hard driving.

Check your thermostat and only replace your O2 sensors from Legit sources like rock auto or URD and LCEngineering, They know what parts are needed and usually is the same as the dealer for less.

 

I put on a cheapie aftermarket and now have a "catalytic converter below efficiency" CEL and a smog due next month. A guy at work went thru the same thing a put a Magnaflow on his Taco without issues. I'll be looking for one this weekend

 

Well I found out that my rear Cat Conv. and O2 sensor are bad. I took it to a shop so they could test the exhaust system and tell me what wasn't working properly. When I got the code (po420) pulled at autozone they said that code meant it could be either a bad O2 sensor on bank 1 (front) or bank 1 Cat Conv. I'm glad I took it in to get tested or else I would have replaced the wrong parts. I'm guessing that the code P0420 doesn't always mean that it's only for the front sensor or cat converter. Heads up to all who have this code on their vehicle. Just because its code P0420 doesn't always mean bank 1, it very well might be bank 2.

I'm gonna go with an aftermarket magnaflow Cat. because I've heard good things. If anyone doesn't think I should please chime in.

Thanks!!!!!!!

 

http://www.urdusa.com/product_info.php?products_id=1230100014

That will fix your issue, without having to get a new catalytic.
Either that, or get a new front o2.

 

Actually this is not uncommon at all. One of the number one causes of your catalytic converter going bad is correlated with not replacing your spark plugs at the recommended interval. Fouled plugs don't properly combust the air/fuel mixture which leads to not only wasted fuel, but unburnt fuel going to the catalytic converter. The unburnt fuel is heated and burnt in the converter basically destroying it and the element inside it.

 

not going to help or fix the problem. like putting a bandaid on a gunshot wound.

 

Replaced spark plugs and both 02 sensors, CEL still on. Started looking for exhaust/intake leaks. Everything good, CEL still on. Then my neighbor came over with a Snap-on code reader that can monitor things in real time. We were watching the pre and post O2 sensors while the engine was running and the post cat sensor was all over the map fluctuating huge numbers. That told me the cheapie cat was not doing its job

 

At what interval did you replace your plugs? If the converter was already damaged because of prolonged plug use, changing the plugs afterwards would obviously not fix the converter.

 

You know that could also mean the sensor is bad. It probably IS the cat, but my O2 sensor on my last truck had a rapidly fluctuating signal when it went bad.

 

If you are going to try to troubleshoot your front/rear HO2 sensors and or cat converter by watching your voltages in real time via scan tool, you need to ensure that the converter is warmed up when you start judging them. When you first start the truck when the converter is "cold", your front and rear HO2 sensors will read virtually the same as far as voltage and switching. However, after a couple minutes of driving, the converter and HO2 sensor should be fully warmed up and functioning and although the front HO2 sensor will fluctuate rapidly, the rear HO2 should not fluctuate to the same voltage extremes or as rapidly. If after a few minutes of driving the front and rear HO2 sensor voltages are switching at the same pace and to the same extremes, it would be safe to assume that the cat converter is not doing its job. USUALLY, the ECM will pick up on this condition and set a code. This is all assuming that the HO2 sensors are heating up properly as they both have heating elements in them, however the ECM monitors the HO2 that they are heating up in the proper timeframe, and will set a code accordingly. I strongly recommend the use of OEM HO2 sensors as I have seen the cheap ones that don't heat up properly or that can be "lazy" in their voltage readings and switching, which can "trick" the ECM into setting false codes causing hard to diagnose drivability issues. Hope that this information is helpful in troubleshooting your problem.

P.S. A faulty rear HO2 will never cause a drivability issue as its only function is to monitor the effectiveness of the cat converter.

 

Bmack, yes the truck was not cold when we were watching the O2 sensors and there were replaced with OEM Denso sensors. The only reason why I don't suspect a faulty new sensor is because a few weeks after the cat was replaced the old sensor triggered the same code. Also you are correct about the drivability as performance or mileage hasn't changed

 

ive had the same code before, replaced upstream sensor and rear 02 sensor and was good, my cats have 275k on them and are still good btw

 

Just had the p0420 code.. turns out it was a bad spark plug..

 

2001 was the transition year that Toyota began making Tacomas with two cats across the board, not just for California. However, the early 2001s had only one cat while later 2001s had two cats.

Another possibility for the P0420 code is an air leak in your exhaust. Inspect the pipes before your second cat for holes and the gaskets at your flange joints. If you see any water leaking from the flange joints, you may just need a new gasket.

 

Why wouldn't it?
All a P0420 is is saying that your catalytic converter isn't efficient enough.
That clears up the p0420.
If nothing else appears except p0420, then why not?

 

I had a p0420 code but I knew that the cat was gutted. Picked up a used but still new Catco Cat and it cleared it right up. Only cost me $30 on Craigslist.

 

You can get away with that in most states
Here in the Republic of Kalifornistan you'd be strung up by your manhood

http://i.imgur.com/b5grOaC.jpg