Issue with car running, please help!

[MakeMeFamous]

So you think the leak is before the first o2 sens then?

We know there is a leak down further in the pipe (temp fixed it with aluminum sheets) but that would only affect the second o2 sens right?

[SL19302]

Originally Posted by MakeMeFamous

So you think the leak is before the first o2 sens then?

We know there is a leak down further in the pipe (temp fixed it with aluminum sheets) but that would only affect the second o2 sens right?

Any exhaust leak from the exhaust manifold to the Converter inlet will upset the fuel mixture, That front pipe needs to be air tight with welds around the joints, Once its repaired or replaced pull the PCM B fuse in the Under hood Fuse Box for 30 Seconds then re-install the fuse and start the engine and see if it behaves differently. Also check the exhaust flange gasket where the pipe bolts to the exhaust manifold as that gasket fails often, Dont run the car with that leak anymore as the rich fuel mixture will burn up the converter.

[MakeMeFamous]

Just took the manifold off. No cracks in it or the gasket, but it was completely missing a flange gasket lol. Think that would do it?

[SL19302]

Originally Posted by MakeMeFamous

Just took the manifold off. No cracks in it or the gasket, but it was completely missing a flange gasket lol. Think that would do it?

Yes the flange gasket where the pipe bolts to the manifold is a common failure, Clean the flange up and install a new gasket, The other leak you were talking about as long as its AFTER the converter it shouldnt affect the engine.

[MakeMeFamous]

Put all new gaskets in and re sealed the hole in the exhaust. It runs so much better, but still isn't perfect lol. Sometimes it still hesitates when pressing the accelerator (meaning that the engine sounds like its gonna stall out for a sec then revs up). But the idle is so much smoother and doesn't shake much lol. Cleared and re-scanned codes and got nothing. Any other ideas on why it's hesitating or still takes a couple tries to start? probably gonna put some fuel injector additive in it tomorrow and let it run for a bit unless you think its still running too rich.

[fdryer]

Mileage? Compression test?

[MakeMeFamous]

113k miles and haven't done a compression test

[fdryer]

A compression test can tell about the condition of the engine, a fuel pressure test will tell you how much pressure is made, and removing spark plugs can tell you if plugs; are worn, fouled in oil, blistered from wrong plug choice, black or soaked in fuel. And a spark test can tell you if all plugs are firing. The gauges may be loaned out from AutoZone in your area.

[SL19302]

With the engine running so rich from the exhaust leak it might not be a bad idea to replace the plugs as they most likely are fouled, While you have them out peform a compression test.