I live in Connecticut, and soon I have to go through emissions testing. Normally that would only be a minor inconvenience, however I have a check engine light that says the catalyst converter efficiency is below the threshold. Furthermore I have noticed a good amount of oil is being burned, especially when during VTEC (I can see a cloud behind me when I accelerate into the VTEC RPMs). I am not sure where to start troubleshooting this problem. My assumption is the oil caused the catalytic converter to mal-function, correct me if I am wrong.

 

yeah your converter is burning oil inside it and that will tear it up.

 

Well I could replace the converter ($1000 +), however the oil is still leaking. Some background information on the car: 97,000+ miles, oil changed regularly...between 45,000 - 60,000 the car had a jackson supercharger. I took the supercharger off because it was creating a lot of hassles and the engine was stock (compression was too high). I believe that is the root of the oil consumption problems. Is there any reason why the oil consumption is more noticable during VTEC?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ctjohn23 &raquo;</TD></TR><TR><TD CLASS="quote">Well I could replace the converter ($1000 +), however the oil is still leaking. Some background information on the car: 97,000+ miles, oil changed regularly...between 45,000 - 60,000 the car had a jackson supercharger. I took the supercharger off because it was creating a lot of hassles and the engine was stock (compression was too high). I believe that is the root of the oil consumption problems. Is there any reason why the oil consumption is more noticable during VTEC?</TD></TR></TABLE>

Oil consumption is more notaceble at higher RPMs because the pressures are higher. All B-series burn a small amount of oil in the big lobes, but if you're seeing a huge cloud it's probably time to do a compressions test, then go from there.

 

Burning oil will kill O2 sensors and catalytic converters. This code is thrown by the ECU monitoring the secondary O2 sensor.

So...did burning this oil kill just the O2 sensor, just the cat...or both? 97k miles on a stock O2 sensor puts it into 'replacement land' anyway - but who knows with the burning oil problem.

If you stay out of VTEC, does it burn near the same amount of oil?

 

I'd change the PCV valve. It's a common cause of burning oil. Also in vtec, it's common to blow oil out the breather hole into the intake manifold. You might want to experiment with running with the breather disconnected and see of the oil cloud goes away.

Cat's not $1000. Worst case it's $700 or so from Majestic. I'd go aftermarket for a couple hundred. Cat efficiency CEL can also be caused by a bad secondary O2 sensor.

You could try an O2 simulator for the secondary O2 to fool the ECU into thinking the Cat's ok.

 

I did a compression test and the results looked good actually ... If I am remembering correctly 195 +- 10PSI across the board. Hmmm... Leaking at the valve guides maybe? I did switch to synthetic oil at one time and then switched back - The synthetic oil was still burning - just more expensive.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">Burning oil will kill O2 sensors and catalytic converters. This code is thrown by the ECU monitoring the secondary O2 sensor.

So...did burning this oil kill just the O2 sensor, just the cat...or both? 97k miles on a stock O2 sensor puts it into 'replacement land' anyway - but who knows with the burning oil problem.

If you stay out of VTEC, does it burn near the same amount of oil?</TD></TR></TABLE>

Well last time I checked the only code related to emissions was related to the converter. Well actually in VTEC land it seems to burn the most oil, if I stay out the oil consumption is not AS bad.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MasterKwan &raquo;</TD></TR><TR><TD CLASS="quote">I'd change the PCV valve. It's a common cause of burning oil. Also in vtec, it's common to blow oil out the breather hole into the intake manifold. You might want to experiment with running with the breather disconnected and see of the oil cloud goes away.

Cat's not $1000. Worst case it's $700 or so from Majestic. I'd go aftermarket for a couple hundred. Cat efficiency CEL can also be caused by a bad secondary O2 sensor.

You could try an O2 simulator for the secondary O2 to fool the ECU into thinking the Cat's ok. </TD></TR></TABLE>

Well I did actually replace the PCV valve thinking that could of caused the oil consumption, however that did not help. Well I think I price checked it at Majestic.. I will check again. I remember something crazy in the 1000's for a stupid converter. Haha.. maybe O2 simulation will help :-) I still have to find the oil consumption problem however.

 

Are you positive its consuming oil? Does the oil level drop damatically over like 1000 miles?

What color is the smoke?

Honda's do run rich, and smoke that looks more black is a sign that you are running rich and not burning oil.

Honda's are known to go thru cats as well. I had that code on my civic EX, and I was still within the federal emission warranty, so Honda replaced the cat for free. They have to warranty emissions devices for like 7 or 8 years or 80k miles.

On top of that, Si's go thru cats even more so. Get a magnaflow cat to replace the stock one, it'll save you hundreds. Or get a used cat that's still in good working condition.

 

My oil consumption went away when I disconnected the breather and used a filter attached to the breather hole. I'd noticed a significant amount of oil in the intake manifold when I took the throttle body off to clean it.

I don't believe guides will cause "on power" oil consumption. If you get a cloud when you let off the gas, then it's probably guides or rings.

After the super, I wonder if the PCV system's hooked up properly.