Would leaking exhaust manifold throw a code? 2004 v8-4.7l...

Q: Would leaking exhaust manifold throw a code?

asked by on March 08, 2018

I have a pretty bad exhaust manifold gasket leak and im getting the code for bad catalyst sensor bank 2. I was wondering if my catalytic converters are bad or if its the exhaust leak that's throwing the code? Also when accelerating my truck bogs and doesnt run good at all.

My car has 139000 miles.
My car has an automatic transmission.

If the exhaust system is not air tight, that will skew oxygen sensor readings and a consequence is a false indication of catalyst efficiency. In addition, the upstream sensor will not be providing a valid reading to the computer insofar as combustion conditions. The invalid inputs to the computer could be a part explanation of the poor performance. Your best course is to fix the manifold leak first and then re-evaluate the engine performance. It may be that additional issues exist but a leaking manifold is going to needlessly complicate the diagnosis. To have the manifold replaced on a mobile basis, right at your location, please request exhaust manifold replacement service. Once that repair is complete, the very same mechanic can perform any additional required diagnostics and thence repairs.

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