Skip the auto shop - Our mechanics make house calls

Q: Spark knock

asked by on

I just had my cats deleted. When I tried opening it up a little while I was driving home it didn't seem to be getting any power and while accelerating I can hear a knock. When I deleted the cats did I cause the spark knock, how do I make sure it's a spark knock, could it have been there before and I just didn't hear it, and what do I need to adjust to get everything running right now that I deleted the cats?also if it wasn't caused by deleting the cats what should I look for, how much engine performance is lost due to spark knock? Thank you for your time.

My car has 190000 miles.
My car has an automatic transmission.

A: If you are getting spark knock then you may...

If you are getting spark knock then you may have a bad mass airflow sensor telling the computer you are at or above 10,000 feet above sea level and would run the engine lean. Have the sensor tested. As far as deleting the catalyst I cannot comment since it would be against the law for me too. However if you were putting in a test pipe for testing only then you would need to somehow bypass the O2 sensors. If you’d like to get some help with this, consider YourMechanic, as a certified technician can help diagnose the noise you’re hearing firsthand.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: Abs and handbrake light staying on

Hi, thanks for writing in. It is possible that the sensor, or another component, was damaged during the repair. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect...

Q: Not getting fire to plugs

Hello, being that you had a blown fuse for the starter and replaced the fuse and starter, I will assume that it cranks over now. For the lack of spark, did you check all your fuses. You could also have...

Q: Change check transmission fluid

Hello there. The Nissan Versa and many newer vehicles do not come equipped with transmission dipsticks. The owner's manual (which comes with the car) should have details for how the CVT transmission fluid is checked, as this is a service...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
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...