Smog Check blues

I failed the California smog check so I paid a mechanic to diagnose the engine and both the oxygen sensor and catalytic converter tested way out of spec. I replaced the oxygen sensor and noticed that the old one has some white and beige corrosion around the base of the probe. The tip of the probe is black and sooty. Is it normal to see corrosion on this sensor?

I seem to be losing both oil and coolant at a slow rate and they're not going on the ground so I'm afraid they're leaking internally and maybe this is an indicator. Not sure how worried I should be about that. I was thinking about trying to find the leaks with UV dye but if they're internal that may be useless.

One thing that apparently was missed at smog check but noticed by the mechanic who did the diagnostics is a small rip in the cold air intake hose. According to the mechanic the laws in California prohibit repairing that hose by wrapping it in duct tape and it must be replaced with another identical stock hose. A generic hose that fits will be considered an "engine modification" and make the vehicle fail the inspection part of the smog check.

It doesn't really leak enough to kill engine performance unless the hose is flexed and the rip stretched open but I'd still like to do something to seal the hole. Is what the mechanic told me true? Is there any way I can repair the hose and still pass smog check?

The mechanic also suggested replacing the spark plugs, wires, distributor rotor and distributor cap. I had to mail order the spark plug wires so I'm waiting for them to replace all those parts. I know this should give me a better spark and maybe more power but is it really going to impact emissions? I'd like to go have the truck re-tested now unless replacing those things could make the difference between passing and not.

How the #^*^$##^*&#$ would an inspection mechanic know what was "factory/stock" on a 25 year old truck? Get a generic hose and dirty it up good.

Emissions are very strict here, I am assuming you have an EFI B2200?

I have never had to replace the O2 sensor on mine but I have taken it out to put on the pacesetter headers (my smog guy thinks the model number is the CARB number so he passes it... I'm not saying anything about it though ) It looked normal when I had it out a while back, no black on it at all just a light brown dusting.

My CAT on the other hand has been replaced 3 or 4 times (only one on an EFI set up) they are pricey and only seem to last me 2-4 years if I'm lucky. I have a 2" exhaust from the headers to the muffler dumping off before the rear axle with the CAT in the center of it all. I am not sure why it only lasts me a short operational period but this my current one even needs to be replaces bec I had to gut it when it broke apart, its only 2 years old!!!

Definitely do the Cyl leak down test and also the Coolant pressure tester as Cusser said.

If the intake hose is ripped up bad then I would say to get a JY one or generic one. If not then try to seal it up descretely with some black RTV or try to seal it up by melting it back together with a soldering gun? IDK, can you take a pic of it and post it on here.

Did it look like this?



Or like "D" here?



If so, that isn't corrosion, it's carbon buildup.
A: New 02 sensor
B: Oil Fouled 02 sensor
D: Carbon Fouled O2 sensor
E: Normal wear O2 sensor

The cause of carbon fouling is a rich condition, or oil consumption. Both will kill cats too!

I thought about trying to get thru smog check with a generic one but it seems like the engine is doing ok right now so I'm hoping to not replace it until after I do smog check.

no, actually it's a 1991 b2600i. Sorry, I should have said that.

black RTV is a good idea. I didn't know they made that but I'll go buy some. That sounds like it will work so I'm optimistic.

I'm afraid I'll need to do a cat replacement too since the mechanic said it's operating at 32% and the specification is 90%, but I'm fixing everything else and then going to test again before I spend all that money.

One thing I was confused about; the mechanic said the cat has to be welded in but mine definitely has bolted flanges on it. Is the mechanic wrong or do new cats normally need to have flanges welded on?

Here is a pic of the old oxygen sensor. I think it appears to be most like photo "d" but with areas that are like "b" and "e."

I do believe I'm burning oil but I have been a little ever since I got the truck 50k miles and six years ago. I add "engine restorer" once in a while and the problem seems to be progressing slowly or improving. Maybe I can just do that yearly and it will stop burning?

Mine is a bolt on (EFI B2200), although they do make some weld on ones. I would try to find a bolt on because at the rate I have to change mine it would suck to have a weld in cat!
Plus there are specific "California Cats" that you have to get, some companies won't ship "49 state legal" cats to Cali.
Cali ones are usually larger/longer than the 49 state cats and twice the price. Try to find some deals on the interweb.

That O2 looks fouled to me, I would replace with a OEM Mazda part and not any generic one.

Sounds like you are on the right track, Keep it up and good luck on your testing!

ok, I just replaced the spark plugs, spark plug wires, distributor cap and distributor rotor. The manual says to gap the plugs per the Emissions Control Information label. I think I found that label on the underside of the hood but the sticker on my truck has no spark plug gap info. So, I decided to leave the plugs how they were gapped from the factory.

Now the engine sounds great at idle but when I accelerate it stumbles and even died once. The only other work I did was to put rubber sealant over a tear in the intake hose but I don't think that would have anything to do with this.

Any idea what's wrong? I need to drive this truck on the highway soon and I'd really like to resolve this before I do.

PS: as soon as I finish the cleaning solution that I put in my fuel tank I'll go back to smog check and let you guys know if I passed. I tried the coolant pressure test last night but couldn't get a good seal between the tester and my radiator. It was losing pressure slowly but I have no idea if it was just leaking at the tester or if I have an internal leak.

Maybe the gap is too large and blowing out the spark?

Coil to dizzy cap seated?

Check timing? may have to ground out a wire to disable electric timing advance.

IDK

Hope you find out soon. Good luck!