I have an EG with a p.o.s d15b8 and it didnt pass smog when i went to get it refd. What could be the problem? It passed everything beside the CO levels

 

I would suspect your EGR system. Either blocked EGR ports or the EGR solenoid is not allowing enough vacuum to open the EGR like it should. Of course the EGR valve itself could be sticking or stuck.

This is a normal problem with the 1.5L.

The other thing I notice is alot of O2. Do you have an exhaust leak? The Cat uses the O2 to tear down the other crap and with leftover O2 out of the pipe one would also suspect the Cat is not up to par, or the O2 sensor is not up to par either. It is the O2 sensors job to vary from rich to lean so the Cat can use the O2 it get's.

I would first check out the EGR system.
EDIT: scratch the EGR stuff. I should of looked at the report closer. You don't have an EGR. Unless he missed it.

So exhaust leak? If it is leaking before your O2 sensor that might be the problem. Also inspect the exhaust manifold by taking off the heat shield and see if there are any cracks between the ports. If no leaks then tune-up, O2 sensor, and cat.


Modified by thesmogman at 2:44 PM 5/8/2008

 

alright
i have a leak but its right about my rear axle
no leaks b4 the cat
the guy at the ref station said it might be b.c i have some dirty *** oil and i need to change it and come back
how much does the average shop charge for an o2 sensor test?

 

They usually classify it as diagnosis and charge the normal flat rate per hour, and of course you can't just pay for a half an hour. Unless you get a break.

They will probably charge as much as a new O2 sensor would cost. You are just over the recommended replacement mileage for the O2 too. I believe it is at 120k.

So the O2 is from a leak, so we can't use that reading to diagnosis the cat.

I guess the tune-up has already been done right? if so just throw an O2 at it.

CO is caused by bad combustion/ignition. That is why I asked about the tune-up.

 

EGR. Honestly the cat looks fine. Check the EGR lines. It usually gets all gumbed up where it goes into the intake manifold.

Easy way to check the EGR is unplug the vacuum line going to the EGR valve and use a vacuum pump or direct manifold vacuum and when it gets full vacuum the engine idle should drop and it might run poorly or die. This means it workly properly. If it does nothing something is wrong.

 

I made that mistake too... he doesn't have an EGR. Sorry if I got you running down that street. But yeah normally you see a 1.5 and high CO it is the EGR.

 

ok well
im gonna give it a reg tune up and buy a new o2 sensor and see how that works out

 

That is where I would start.