Power loss

[Antonio757]

I have a 2002 Chevy Tahoe and I just replaced the exhaust system with a maganaflow. The problem I’m have is that I’m experiencing a major power loss when I’m accelerating after being stopped. Any idea as to what may cause this?

 

[B-train]

Are there any engine codes present? Maybe fuel pressure? Also, a high flow exhaust may make the truck drive diffently than the OEM. Are you sure that you're just not hearing more noise than normal, leading you to believe you should be going faster?

 

[StormTrooprSubZ71]

If the problem started after your exhaust install check your O2 sensors, did they leave them unconnected. Do you still have your catalytic convertor installed? If your exhaust is too free flowing you might not have enough back pressure.

 

[Marky Dissod]

I have a '02 Tahoe and I just replaced the exhaust system with a magnaflow.
The problem I’m have is that I’m experiencing a major power loss when I’m accelerating after being stopped.
Any idea as to what may cause this?

Can you compare the OE exhaust system to the magnaflow?
If your exhaust is too large in the wrong place(s) it may not have enough SCAVENGING.

 

[Antonio757]

Are there any engine codes present? Maybe fuel pressure? Also, a high flow exhaust may make the truck drive diffently than the OEM. Are you sure that you're just not hearing more noise than normal, leading you to believe you should be going faster?

There’s no engine code but the service engine light is blinking. The scanner from Auto Zone didn’t pick any up. Not sure why. It’s definitely a problem. I filled up my tank about 4 pm yesterday and ran out of gas 10 am this morning.

 

[Antonio757]

Can you compare the OE exhaust system to the magnaflow?
If your exhaust is too large in the wrong place(s) it may not have enough SCAVENGING.

I’m not sure what that means exactly but I had it installed by a shop.

 

[Antonio757]

If the problem started after your exhaust install check your O2 sensors, did they leave them unconnected. Do you still have your catalytic convertor installed? If your exhaust is too free flowing you might not have enough back pressure.

The O2 sensors are new and the cats are new also. I went through a tank of gas in less than 24 hours.

 

[Joseph Garcia]

I do not believe that the replacement of only the muffler itself would cause any backflow pressure change issues that would significantly cause negative performance.

I believe that something else changed with the installation of the muffler. If you are getting a service engine light, there must be underlying trouble codes that are causing it to light. I'm not sure what scanner you are using, but if it is not a full service bi-directional scanner, it is probably missing the trouble codes that are present.

 

[Fless]

I do not believe that the replacement of only the muffler itself would cause any backflow pressure change issues that would significantly cause negative performance.

I believe that something else changed with the installation of the muffler. If you are getting a service engine light, there must be underlying trouble codes that are causing it to light. I'm not sure what scanner you are using, but if it is not a full service bi-directional scanner, it is probably missing the trouble codes that are present.

^^x2^^

Any issues prior to the exhaust install?
How many miles or hours did it take to drink the full tank of fuel?
Were the catalytic converters retained?
Are the oxygen sensors connected and working?

 

[strutaeng]

but the service engine light is blinking. The scanner from Auto Zone didn’t pick any up.

Service Engine blinking means you have a misfire and running the vehicle like that will inevitably damage your new catalytic converters!

So try to figure out why you have a misfire is your underlying issue, but there may be more issues. Once you fix that, your power will come back.