Gaskets?

[footee]

I had to pull my exhaust to drop my tranny for a clutch change. I didn't install new gaskets from the y pipe to manifolds. It does sound like it's leaking a little but will that cause a trouble code? I have a couple o2 censor codes, p1131 and p1151, didn't know if that could be caused by the missing gasket/leaks.

 

[monstermazda]

Shouldn't throw codes up but it's always best to have it sealed for winter can cause a back fire affect when shifting. Ifs a big leak

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[footee]

Copy that, thank you!

 

[alwaysFlOoReD]

The exhaust isn't going thru in a steady stream, but in pulses. In between pulses is low pressure which can suck in outside air throwing off the o2 sensor.

 

[footee]

I ended up replacing both upstream o2 sensors and as it turns out, one was broken. I also installed a gasket downstream between the cats and tailpipe. I can't hear any exhaust leaks now. Parts store didn't show a gasket at the y-pipe to manifold so I'm assuming there isn't one there, correct? Due to the flare on the pipe...