1993 3.2l SHO badly failed emissions.

[Ksoder]

Hello, This is my first post as a day 3 SHO owner, so its sad to have to introduce my car in the emergency help section...

I have a 1993 SHO Automatic with the 3.2l and just went to have emissions done to register the car and things went horribly...

Here were the first set of results...

Hydrocarbons (g/mi) 4.02 where 1.00 is max

Carbon Monoxide (g/mi) 94.55 where 12.00 is max

NOX (g/mi) 5.14 where 2.5 is max


After getting these rather discouraging numbers, I went home with much worry, once home, I realized my CIL had come on so I ran the code which came out to be #332 Insufficient EGR Flow Detected. I then immediately realized that my green vacuum line running to my EGR valve was disconnected from the (not sure what it is but its got a red wire running directly into the manifold and the green one to my EGR valve). So, I plugged it back in and thought "Aha, gotcha!" Little did I know, I did not indeed "gotcha".

Second set of results

Hydrocarbons (g/mi) 3.33 where 1.00 is max

Carbon Monpxide (g/mi) 65.58 where 12.00 is max

NOX (g/mi) 4.75 where 2.50 is max


Im pretty sure those numbers mean I am running super rich so I was thinking O2 sensors, cats, MAF, busted Fuel Pressure Regulator Diaphram, and the usual stuff, so before I go diving into unnessecary repairs, what do you guys think is the issue here? Thanks

 

[luigisho]

Are there any more codes stored in the computer? The first thing I would look at is clogged EGR, clogged passage at the intake manifold from the egr vacuum hose, faulty/clogged hoses to from EGR and work down from there.

Not sure if this link will work but if it just takes you to the parts section put your year/make/model in and when you click on emission system it will show you the parts with schematics on most of the hard parts of the system to give you a physical point of reference on what you're looking at.
https://parts.lakelandford.com/a/Fo...SSION-SYSTEM-EMISSION-COMPONENTS/JN92590.html

I'm still looking for the entire diagram somewhere. I have only had MTX cars 89-95 without egr.

I don't see a dpfe sensor in the diagram and not sure it's in the early setup, but I would think so. Hopefully atx egr people will chime in.

 

[zoomlater]

Pull your codes so you have a better idea what is causing your issues. You can read through these threads on EGR issues. I used pipe cleaners and carb spray to clean the tubes below the DPFE sensor. Or you can try pulling the spout connector to see if that allows you to pass

https://shoforum.com/index.php?threads/egr-cleaning-and-other-questions.127092/

https://shoforum.com/index.php?thre...e-smoke-now-smog-failure.125484/#post-1391480

 

[sperold]

You usually get a dash light when the 02 sensors are bad. if you replace them, purchase Denso or Ford Motorcraft.

That EGR is a must to have working, and often it is the tube that connects the exhaust manifold to the component. The nostrils in the intake can be an issue, and it is usually a matter of cleaning them up, a no cost fix.

I would pull the spout (spark out circut) which sets the timing at 10 degrees and rewards you with better emissions results.

A new pair of catalytic converters will pretty well guarantee a pass, but it is an expensive option.

I always got best results by scheduling the test, then driving a long distance (an hour or two) right before the test.

Is the test on an dynomometer, or the 2 speed chemical-type test, sitting still? The dyno test is rigorous and hard to pass without preparations.

 

[rubydist]

We need a little more information to be of more help.
1. how does the engine run? I expect it has some significant misfire, but you did not mention that.
2. how do the plugs and wires look? I expect they need replaced.
3. what is the condition of the coils?
4. how long since the timing belt was changed?
5. have you verified the cam timing is correct?

You are correct that it is running way rich to get those kinds of numbers. Oxy sensors can fail reading too rich or too lean, but you cannot get rich enough to get those results with just bad oxy sensors. There is more going on than that, because to get that rich with just fueling, you would get the fuel trim limit codes.

This is why I am asking about plugs and wires. You cannot get that rich without some kind of incomplete combustion. Plugs and wires would be the easiest possibility.

The other thing that could be going on is cam timing could be off. It doesn't take much (a couple teeth) on the cam timing to get the engine to run crappy and make the emissions get way out of wack. That is why you need to verify cam timing is correct.

 

[luigisho]

SPOUT helps with pulling timing but I don't think it will move those numbers enough. Maybe but that's alot out of range. rubydist has good ideas and I could not agree more that the mix, especially CO is really out there.

 

[Ksoder]

Hello all, thanks for the replies, ill clear up a lot of stuff...


1) the engine is running totally fine, no obvious misfires and no engine code for them, starts up faster than any other car I own and spins the front tires better than my mustang spins the back ones haha

2) I pulled the front 3 plugs, one of the wells had a little bit of oil in it (valve cover gasket) but not enough I am worried about it. The plugs looked like a hazelnut brown and didn't have any type of oil looking buildup on them and I'm not sure how to test the coils.

3) the engine codes read as such. 111 (all good) - 10 (spacer code) - 332 (egr system). There were no other codes


The car was registered as of Dec. 2018 so its only been about a year. The PO removed the mufflers and replaced one side with a magnaflow glasspack and the other with a straight pipe, which I didnt think would matter because mufflers don't typically change emissions. You can smell the richness of the exhaust and it kinda burns your eyes when you're behind the exhaust pipes for a bit. As for the timing belt, I can't even try to comment on that, because ive only had the car 3 days.

I've rebuild engines and stuff and complete suspension overalls so I would definitely say I'm good with cars, with that in mind, how hard would it be for me to change the timing belt and are the 3.2l SHO's interference engines?


I pulled the vacuum hose off the fuel pressure regulator and there was no gas in it so I think im good there, and I checked vacuum from the intake manifold to the EGR (vacuum switch?) And the red line has solid vacuum, the green one coming through the switch has only a little bit of like pulsing vacuum and when I unplugged the electrical connector from the "switch" it didn't change the amount of vacuum on the green line.


Lastly, it is a Dynometer test but hey, at least my gas cap passed

 

[luigisho]

Not interference engines.

Are the cats still on the exhaust? If it's rich enough to burn your eyes then too much fuel is not being burned and I would be concerned about all that fuel in the catalytic converters if they are on the car. Go over the egr parts as there can be enough crud built up to make them ineffective.

There should normally be enough spark and air to combust the fuel.

 

[sperold]

About 6 years ago, we had the Dyno test replaced by the 2 speed engine only test.

Cars that had failed for 4 years and received conditional passes based on repair efforts, suddenly passed the test with absolutely respectable numbers.

Your codes are telling you the truth. You must get the Exhaust Gas Recirculation (EGR) system working satisfactorily.

I have heard you can take a temperature reading at the beginning of the cats and at the exit (with a hand held meter) and if there is no temperature change, the cats are dead. But I have never done it myself. That test would be just for your own curiosity.

I have almost passed with terrible cats (missed one category by 5 units), and I have failed with brand new cats, so it is not always the answer.

Don't be discouraged by your terrible numbers. My experience has been that when 1 thing is wrong, your numbers can be atrocious, but fix that one thing, and everything is rosy.

 

[Ksoder]

Here is a picture of my O2 sensor right next to the oil filter, white except matte black at the base, not sure if it needs replacing?


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[rubydist]

Thanks for the details.

1. My experience is that oil in the plug wells is actually a pretty serious problem in that it causes the spark to short out through the oil to the head, rather than making the spark plug actually spark properly. Note that it may be fine at idle, but not at higher loads. A weak spark means incomplete combustion and therefore increased emissions. My guess is the back 3 plugs have more oil in the wells because that's just how things work - the harder to fix areas break first... So, I think it needs valve cover gaskets, plugs and wires.

2. The engine is not an interference engine. You can confirm cam timing by simply removing the top timing belt cover and rotating the engine over until the 2 marks on the cam sprockets line up with the marks on the metal part of the timing cover. Then look at the timing mark on the crank pulley to see if it is lined up or not. I have seen engines with one cam correct and the other off a tooth or two... They need to be spot on. Changing a timing belt on this car is a 3/5, not a problem for an experienced mechanic if you just take your time.

3. The oxy sensor looks to have been in there a long time. I would change those too. iirc, there are 2 different ones called out, a longer lead wire on one and a shorter lead wire on the other. I recommend buying 2 of the ones with the longer lead wire.

 

[Ksoder]

Thanks for the details.

1. My experience is that oil in the plug wells is actually a pretty serious problem in that it causes the spark to short out through the oil to the head, rather than making the spark plug actually spark properly. Note that it may be fine at idle, but not at higher loads. A weak spark means incomplete combustion and therefore increased emissions. My guess is the back 3 plugs have more oil in the wells because that's just how things work - the harder to fix areas break first... So, I think it needs valve cover gaskets, plugs and wires.

2. The engine is not an interference engine. You can confirm cam timing by simply removing the top timing belt cover and rotating the engine over until the 2 marks on the cam sprockets line up with the marks on the metal part of the timing cover. Then look at the timing mark on the crank pulley to see if it is lined up or not. I have seen engines with one cam correct and the other off a tooth or two... They need to be spot on. Changing a timing belt on this car is a 3/5, not a problem for an experienced mechanic if you just take your time.

3. The oxy sensor looks to have been in there a long time. I would change those too. iirc, there are 2 different ones called out, a longer lead wire on one and a shorter lead wire on the other. I recommend buying 2 of the ones with the longer lead wire.

I'm interested about the spark plug situation but have some thoughts.... On emissions, my carbon monoxide is where its REALLY killing me, but wouldn't unburnt gas be producing more hydrocarbons not CO?


Im also looking at my EGR pressure sensor right now and am thinking about replacing it, thoughts?

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[luigisho]

I think at this age all parts are suspect. I would also look at the dpfe sensor.

High CO numbers are usually the result of incomplete combustion. So ignition, air, fuel mix based on faulty components or readings. That also assumes motor is already in time to properly ignite fuel and open/close valves at the correct 'time'.

Oil shorting out the plugs is always a concern with those leaks. Sometimes you can see carbon tracks on the outside of the plug where the spark is travelling outside the plug and sometimes not.

 

[rubydist]

The egr issue on these engines is usually due to the little passages getting clogged up, rather than the sensor going bad, but the sensor is certainly a possibility.

All of your numbers are way out of wack. Keep in mind a healthy engine with good cats will be closer to 10% of the limits, not close to them, so yours has issues with all categories. This is consistent with significant unburned fuel and partially burned fuel.

 

[Ksoder]

The egr issue on these engines is usually due to the little passages getting clogged up, rather than the sensor going bad, but the sensor is certainly a possibility.

All of your numbers are way out of wack. Keep in mind a healthy engine with good cats will be closer to 10% of the limits, not close to them, so yours has issues with all categories. This is consistent with significant unburned fuel and partially burned fuel.

So how would you recommend I go about fixing the unburned fuel issue?

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[luigisho]

To start, plugs, wires, no oil leaks on either of those 2, check timing. O2 sensors, MAF clean, what else adjusts fuel trims? Leaky injector? You can get in the weeds. Do the easy stuff and clean out replace the egr stuff that actually gave you a code.

 

[Ksoder]

To start, plugs, wires, no oil leaks on either of those 2, check timing. O2 sensors, MAF clean, what else adjusts fuel trims? Leaky injector? You can get in the weeds. Do the easy stuff and clean out replace the egr stuff that actually gave you a code.

Should I do everything all at once? And would it be worth it to find an emissions place that doesn't do the dyno test?

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[rubydist]

pretty sure in your situation you are required to do the dyno test.

I would do valve cover gaskets, plugs, wires, and verify cam timing as a starting point.

 

[Ksoder]

Hello all...

I took my inyake manifold off to get at my valve covers and this piece was sandwiched between my IAC and my intake manifold, I broke the ****** off it when trying to remove the hose (i know, impressive) and don't know where to find another one or what its called or what it does, can someone help me out?


Also, the oil was about an inch past the hatching on the dipstick and was WAY overfilled, so I drained it all and replaced the oil filter before filling it back up, im not sure if it's related but the inside of my intake manifold and in my runners, theres a thick layer of oil and oily sludge, is that from my overfilled engine and what else do I need to replace that could have gone bad due to the oil? Thanks

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[zoomlater]

That gasket is supposed to be there. you can probably get a used replacement from Dan Barbush.
How much oil did you add when you did the replacement?
The insides of the intakes and runners get that way normally.