Q: Bypassing catalytic converter with a test pipe

asked by on

Is it bad to bypass my catalytic converter with a test pipe? I use an oxygen sensor spacer to avoid the check engine light coming on. Can this cause any problems?

This is against the law. You are not supposed to give it in catalytic converters. That’s why it’s called a test pipe. People put them on as a test and then if the car runs better, they know that the cap’s gone and then they replace it. Of course, there are a lot of places, like Montana, where no one ever checks it. The people there tell me they take them off and they drive them and the vehicles run fine. The Check Engine Light might come on but you are breaking the law, so you are not supposed to do that. If you want to have the Check Engine Light inspected and properly resolved, a technician from YourMechanic can come to your home or office to perform these services.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Bypassing catalytic converter with a test pipe

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Should I straight pipe because my cat is broken

I'm sorry to say, you're just going to have to bite the bullet and get new catalysts. The same thing happened to my own car just a few months back. That's usually what happens at about the mileage you have...

Q: Catalyst system Efficiency - P0420 - 2010 Ford Fusion.

Hello and thank you for contacting Your Mechanic. For the code P0420 to come on, there could be a lot of issues that could arise to a non functioning catalytic converter. Before you decide to replace the catalytic converter, consider...

Q: Car stalls and sputters while in idle

Claimed by Kevin Gainer

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...