Passed CA Smog!!!

[Tom]

Hi everybody,

I just failed smog yesterday on my 1987 944 Turbo—just a couple of days after purchasing the car I’ve been hoping to get for a very long time. I’m new to the 944 world and was hoping to get some advice from those of you who may have already tackled these issues.

The engine was rebuilt 16k miles ago, so I’m hoping there aren't any vacuum leaks on the engine itself, but you never know. It has a fairly new 3" exhaust with a Lindsey Racing high-flow, CARB EO-approved catalytic converter. The smog technician mentioned there might be an exhaust leak.

I probably made a rookie mistake by not getting the cat fully warmed up—I only drove the car for about 5 minutes and then let it idle for 5 to 10 minutes right before the test.

Anyway, is anyone able to point me in the right direction based on the test results below?

I'm based out of Ventura, CA.

Thanks for all your insights!
Michal
smog.png

Welcome to Carpokes! You’ve come to the right place. Sorry the car failed so badly, but I’m sure we can help get you sorted out.

Before the technical bits, California law expressly puts the responsibility on the seller to provide the buyer with a valid smog certificate before or at the time the car is delivered. An “as is” provision --or even an agreement saying that the buyer is responsible for smog-- probably does not shift that obligation. Just FYI if that's not on your radar.

As for the test results, they look very much like the catalytic converter is doing essentially nothing, and that the car may be in need of a tune-up to boot. Re the Lindsey Racing cat, I'd question if it's really CA-legal (and either way, I doubt it is doing much). The cats listed on LR's site are not CA-legal (though they may offer others not listed). It's not smog legal to go up in size to 3" like that. I'm also not aware of anyone selling a "high-flow" cat with CARB certification for the 951 (and the EO's commonly prohibit advertising approved cats as 'high-flow'). I'd get underneath the car and take some pics the converter, particularly any numbers stamped or engraved on its shell. A modern California-approved aftermarket converter should have a permanent CARB Executive Order number. There are two separate issues involved really. Is your cat working? Sure doesn't look like it is. Is your cat technically CA-legal? Easy enough to check.

You might also want to post pictures of the engine bay. What is the engine’s configuration? Most 951s with 3-inch exhausts have also been chipped or otherwise modified. Might be helpful to see what you have going on. Well-executed modifications should not, by themselves, produce such bad smog numbers. However, a rich tune (very common with hot-rodded 951s), misfires, leaking injector, sluggish oxygen sensor or other engine problem can destroy an aftermarket converter very quickly—California or federal -- and you'd want to fix any/all of that before throwing another (expensive) cat in for slaughter....

I would start with a basic tune-up -- cap, rotor, plugs, wires, air filter, fresh oil, good O2 sensor, stock chips and stock engine management parts (air flow meter, fuel pressure regulator, injectors, etc.). Then confirm that the car is actually entering closed-loop operation when warm and that the oxygen-sensor voltage is repeatedly moving back and forth between rich and lean. We can walk you through that if necessary. Also make sure you have 17-18 inches of vacuum (at sea level) and investigate for leaks if low. That alone might get you close on the test, but you'll likely need a new cat as well (and technically need one either way if the current one isn't actually ca-legal).

[MchBt]

Hi everybody,

I just failed smog yesterday on my 1987 944 Turbo—just a couple of days after purchasing the car I’ve been hoping to get for a very long time. I’m new to the 944 world and was hoping to get some advice from those of you who may have already tackled these issues.

The engine was rebuilt 16k miles ago, so I’m hoping there aren't any vacuum leaks on the engine itself, but you never know. It has a fairly new 3" exhaust with a Lindsey Racing high-flow, CARB EO-approved catalytic converter. The smog technician mentioned there might be an exhaust leak.

I probably made a rookie mistake by not getting the cat fully warmed up—I only drove the car for about 5 minutes and then let it idle for 5 to 10 minutes right before the test.

Anyway, is anyone able to point me in the right direction based on the test results below?

I'm based out of Ventura, CA.

Thanks for all your insights!
Michal
smog.png

Welcome to Carpokes! You’ve come to the right place. Sorry the car failed so badly, but I’m sure we can help get you sorted out.

Before the technical bits, California law expressly puts the responsibility on the seller to provide the buyer with a valid smog certificate before or at the time the car is delivered. An “as is” provision --or even an agreement saying that the buyer is responsible for smog-- probably does not shift that obligation. Just FYI if that's not on your radar.

As for the test results, they look very much like the catalytic converter is doing essentially nothing, and that the car may be in need of a tune-up to boot. Re the Lindsey Racing cat, I'd question if it's really CA-legal (and either way, I doubt it is doing much). The cats listed on LR's site are not CA-legal (though they may offer others not listed). It's not smog legal to go up in size to 3" like that. I'm also not aware of anyone selling a "high-flow" cat with CARB certification for the 951 (and the EO's commonly prohibit advertising approved cats as 'high-flow'). I'd get underneath the car and take some pics the converter, particularly any numbers stamped or engraved on its shell. A modern California-approved aftermarket converter should have a permanent CARB Executive Order number. There are two separate issues involved really. Is your cat working? Sure doesn't look like it is. Is your cat technically CA-legal? Easy enough to check.

You might also want to post pictures of the engine bay. What is the engine’s configuration? Most 951s with 3-inch exhausts have also been chipped or otherwise modified. Might be helpful to see what you have going on. Well-executed modifications should not, by themselves, produce such bad smog numbers. However, a rich tune (very common with hot-rodded 951s), misfires, leaking injector, sluggish oxygen sensor or other engine problem can destroy an aftermarket converter very quickly—California or federal -- and you'd want to fix any/all of that before throwing another (expensive) cat in for slaughter....

I would start with a basic tune-up -- cap, rotor, plugs, wires, air filter, fresh oil, good O2 sensor, stock chips and stock engine management parts (air flow meter, fuel pressure regulator, injectors, etc.). Then confirm that the car is actually entering closed-loop operation when warm and that the oxygen-sensor voltage is repeatedly moving back and forth between rich and lean. We can walk you through that if necessary. Also make sure you have 17-18 inches of vacuum (at sea level) and investigate for leaks if low. That alone might get you close on the test, but you'll likely need a new cat as well (and technically need one either way if the current one isn't actually ca-legal).

Hi Tom,

Thanks for welcoming me and for such an in-depth response. I really appreciate it!

That being said, is a 'basic tune-up' something I can do on my own to keep costs down, assuming I'm willing to spend time researching and tackling it myself?

[Tom]

Hi everybody,

I just failed smog yesterday on my 1987 944 Turbo—just a couple of days after purchasing the car I’ve been hoping to get for a very long time. I’m new to the 944 world and was hoping to get some advice from those of you who may have already tackled these issues.

The engine was rebuilt 16k miles ago, so I’m hoping there aren't any vacuum leaks on the engine itself, but you never know. It has a fairly new 3" exhaust with a Lindsey Racing high-flow, CARB EO-approved catalytic converter. The smog technician mentioned there might be an exhaust leak.

I probably made a rookie mistake by not getting the cat fully warmed up—I only drove the car for about 5 minutes and then let it idle for 5 to 10 minutes right before the test.

Anyway, is anyone able to point me in the right direction based on the test results below?

I'm based out of Ventura, CA.

Thanks for all your insights!
Michal
smog.png

Welcome to Carpokes! You’ve come to the right place. Sorry the car failed so badly, but I’m sure we can help get you sorted out.

Before the technical bits, California law expressly puts the responsibility on the seller to provide the buyer with a valid smog certificate before or at the time the car is delivered. An “as is” provision --or even an agreement saying that the buyer is responsible for smog-- probably does not shift that obligation. Just FYI if that's not on your radar.

As for the test results, they look very much like the catalytic converter is doing essentially nothing, and that the car may be in need of a tune-up to boot. Re the Lindsey Racing cat, I'd question if it's really CA-legal (and either way, I doubt it is doing much). The cats listed on LR's site are not CA-legal (though they may offer others not listed). It's not smog legal to go up in size to 3" like that. I'm also not aware of anyone selling a "high-flow" cat with CARB certification for the 951 (and the EO's commonly prohibit advertising approved cats as 'high-flow'). I'd get underneath the car and take some pics the converter, particularly any numbers stamped or engraved on its shell. A modern California-approved aftermarket converter should have a permanent CARB Executive Order number. There are two separate issues involved really. Is your cat working? Sure doesn't look like it is. Is your cat technically CA-legal? Easy enough to check.

You might also want to post pictures of the engine bay. What is the engine’s configuration? Most 951s with 3-inch exhausts have also been chipped or otherwise modified. Might be helpful to see what you have going on. Well-executed modifications should not, by themselves, produce such bad smog numbers. However, a rich tune (very common with hot-rodded 951s), misfires, leaking injector, sluggish oxygen sensor or other engine problem can destroy an aftermarket converter very quickly—California or federal -- and you'd want to fix any/all of that before throwing another (expensive) cat in for slaughter....

I would start with a basic tune-up -- cap, rotor, plugs, wires, air filter, fresh oil, good O2 sensor, stock chips and stock engine management parts (air flow meter, fuel pressure regulator, injectors, etc.). Then confirm that the car is actually entering closed-loop operation when warm and that the oxygen-sensor voltage is repeatedly moving back and forth between rich and lean. We can walk you through that if necessary. Also make sure you have 17-18 inches of vacuum (at sea level) and investigate for leaks if low. That alone might get you close on the test, but you'll likely need a new cat as well (and technically need one either way if the current one isn't actually ca-legal).

Hi Tom,

Thanks for welcoming me and for such an in-depth response. I really appreciate it!

That being said, is a 'basic tune-up' something I can do on my own to keep costs down, assuming I'm willing to spend time researching and tackling it myself?

Absolutely yes -- in fact, with the 951, the sooner you get comfortable digging in on your own, the better. These cars reward hands-on owners. Do you know what chips are in the car and/or what has been modded vs. still stock? If unsure, post pics! The 951 community here knows these cars inside and out, so can help you with every step of the way (without snark, search police, bad guesses, etc.). We can also give you a good sense where you can save money on parts and where you are better off saving elsewhere...

[MchBt]

Hi Tom,

I have spoken to a Porsche mechanic and had him take a look at the car itself. He pointed out following issues:

1. The mixture is too rich. The NOx numbers were way too high on the smog test, pretty much 3x the max allowed. It has a Lindsey Racing catalytic converter, but the guy thinks it's been completely burned out based on the smog report. I'm not sure if that is the case.

2. There is a small leak on the engine; he didn't tell me any specifics.

3. The exhaust could use some tightening; it might not be 100% tight all the way to the cat. The smog technician mentioned it would be somewhere under the downpipe.

Since I am in a little time crunch to get things corrected in next 21 days, what would you reccomend?

Thank you,
Michal

[Tom]

Hi Tom,

I have spoken to a Porsche mechanic and had him take a look at the car itself. He pointed out following issues:

1. The mixture is too rich. The NOx numbers were way too high on the smog test, pretty much 3x the max allowed. It has a Lindsey Racing catalytic converter, but the guy thinks it's been completely burned out based on the smog report. I'm not sure if that is the case.

2. There is a small leak on the engine; he didn't tell me any specifics.

3. The exhaust could use some tightening; it might not be 100% tight all the way to the cat. The smog technician mentioned it would be somewhere under the downpipe.

Since I am in a little time crunch to get things corrected in next 21 days, what would you reccomend?

Thank you,
Michal

High NOx is usually a result of lean mixtures, not rich. Your other reading do suggest it is running rich, however. More importantly, the fact that everything is over the limit supports the suspicion that your cat is burned out. I think that is a near certainty honestly. What happens in 21 days? As for your 3 points: 1) I agree the cat is likely dead. 2) without knowing what’s leaking that doesn’t tell you much of anything really (I can think of 5 different fluids, exhaust, vacuum/boost —probably more I’m forgetting). 3) exhaust leaks generally give themselves away with soot — has anyone looked?

What to do? If time is short, I’d bite the bullet and have a new CA-legal cat installed — see above for available options. The CA cats cost a lot more than the generic ones, so brace yourself. I’d order it from summit and have a local exhaust shop weld it in. Before doing that, I’d give it a full tune up — cap, rotor, plugs, wires, air filter, O2 sensor and oil change. And confirm you have good vacuum at idle and the car is running in closed loop when cruising and no exhaust leaks. Don’t put an expensive new cat on a poorly running motor — it can compromise the cat and will likely not pass smog either way.

That’s your best shot at passing in 21 days. You could try getting by on some of your existing parts but that consumes a lot of time re-testing etc., and from your description it’s not unlikely your car will need that to pass ultimately anyway…