taxidave

I took my 91 XJ Limited to get smogged and now is a gross polluter.
Evap and visual passed but the emissions came out like this:

-------%CO2 - %O2 ----- HC (PPM) ----- CO% ------NO (PPM)
__ RPM MEAS- MEAS- MAX/ GP/ MEAS- MAX/ GP / MEAS -MAX/ GP/ MEAS
15 1619 10.7 - 0.1 - 86 / 310/ 180 - 0.73/ 2.03/ 6.38 - 711/ 1800/ 118
25 1592 11.5 - 0.0 - 103/ 260/ 175 - 0.93/ 2.23/ 4.99 - 613/1600/ 114

Any ideas would help. Also I noticed oil on my air filter coming from the tube that connects the valve cover.
Thanks

1976Mustang

First things that come to my mind, internal oil leak (AKA you're burning oil), and/or a bad Cat.

That oil in the filter is a faulty PCV valve, shouldn't affect your emissions. But its worth fixing if you can find the parts.

taxidave

When I recently replaced my rusted springs, I took off the back part of the exhaust at the flange at the cat for some room to work. I didn't replace the gasket. Would that have an effect?

1976Mustang

Shouldn't, since they test the exhaust coming out of the tailpipe. But i would replace that gasket anyways, just as a safety thing.

taxidave

I just did an OBD I scan it it showed
"51 - Sustained lean air/fuel ration condition detected in o2 sensor bank 1 position 1.

ZINGGG

CCV****

Hmm you should replace that gasket. You may have a small exhaust leak, causing the air/fuel ratio to be thrown off. Ever replaced the upstream o2?

Bbasso

replace O2 sensor and see if that helps.

taxidave

We know it's a CCV, the parts stores call it PCV.


Will replace the gasket I haven't replaced the o2 sensor yet. I already ordered the NGK 23023.

ZINGGG

Good deal, that might very well be your whole issue right there.

taxidave

Also the CCV elbow that goes to the intake (the elbow closer to the firewall) looks pretty bad too. It appears to be a different elbow than the front one. The parts stores only list the one for the front.

ZINGGG

Yep, it's supposed to be that way. The rear is a dealer only part I hate to tell you.

taxidave

I wonder if it will cost more than the O2 sensor I'm getting from Amazon.

ZINGGG

Haha nah man it won't be. It'll cost you $5 tops I would think

DieselD

Man I'm glad we don't have testing.... yet

taxidave

That'll be a first. I bought a pinion nut that cost more than the impact socket I bought to put it on.

Update: I replaced the front CCV elbow, air filter, cleaned the air box and cleared the codes. I took it for a drive (non-freeway) to Starbucks and back and the scanner now shows no codes, all systems running properly.