A few questions.. long post

[cdc]

The previous owner of my stealth es installed a lower mileage DOHC engine into the car, I am not sure if the car came with a DOHC engine originally or if it had a SOHC.
Can anyone tell me which engine this car should have?

I am getting codes 21 Engine coolant temperature

11 Oxygen sensor I have checked the voltage and the front shows about 5 volts but the rear shows about 0.03 volts. Does this mean the rear O2 needs replacing?

41 Injector circuit I have checked the injectors with mmcd and they all change the sound of the engine when tested individually so what else could be causing this?

43 EGR This is my main problem being in Cali, should my car have a EGR from the factory? The new engine has it on the back but there is no solenoid on the firewall to control it and the exhaust pipe on the back of the EGR has been sealed. Some of the vacuum pipes on the top of the throttle body have been looped back.

I need to fix these codes as I wont pass a smog check any help would be much appreciated.

[skater334]

Ok for the motor....google is your friend.

Replace your thermostat and your O2, double check your injector clips w/ a voltmeter, and here's the diagram/write up for the EGR.

http://www.asashop.org/autoinc/nov97/gas.htm

[RL7]

I'm think all es models came with a dohc and only base models had sohc engines.

[Steve '92ES]

Ok, a couple things.
First, as RL7 said, all ES models were DOHC. You should be OK there.

Second, first gen DOHC did not have a rear O2 sensor. Ignore that if your seeing it on a logger.

Third, be careful with that code 41. That tends to pop up when the ISC goes bad. I'm not sure why but a bad ISC can wipe out the injectors drivers. If I were you I'd ohm test the ISC pronto and unplug it if it's shorted.
From Stealth316.com http://www.stealth316.com/2-isc-iac.htm

2. ISC servo. Press down on the release lever of the wiring harness connector and pull it off the ISC servo. You may have to wiggle it a little as you pull. Do not pull on the wires. At this point you can test the resistance of the four coils or wait until you have the ISC servo off the throttle body. To perform this test, measure the resistance between terminals 2 and 1, between 2 and 3, between 5 and 4, and between 5 and 6. The resistance should be in the range of 28 to 33 ohms for the original and older models, and ~40 ohms for the most recent model, which is after our 3S cars were manufactured (see http://www.dsmisc.com/). The results for me were 30.1, 30.1, 30.3, and 30.4 (same order as given above) with the ISC servo off the throttle body.

Be sure to check it both stone cold and warmed up...

Forth, yeah, all Cali spec came with an EGR :(
First thing you'll want to do is make sure it came from the factory as a Cali spec car.
Look at the Vehicle Information plate on the driver's side firewall. If the last two digits of the Model Number are "2D" then it shipped as a Fed Spec. If they're "7D" then it's a Cali.
Next check the ECU, to make sure it's the right one.
If it's a MD159963 or MD190662 (depending on year) it's a Fed spec ECU.
If it's a MD159962 or MD188204 (depending on year) it's a Cali spec ECU.

That should be enough to start with... ;)

[stealthee]

With all of those codes it sounds like you have a bad ECU.

The easy way to tell if your car was a SOHC or DOHC from the factory is to look at the rear quarter windows. If is says 24V DOHC on the quarter window then that answers your question.

Another way would be to look at the gas lid. if it says Premium Fuel only then it also indicates the car came from the factory with a DOHC.

[Steve '92ES]

With all of those codes it sounds like you have a bad ECU.


Or the wrong ECU...

[stealthee]

Possibly, but I had the right ECU in my TSI and when the ECU went tits up I got a lot of the same codes he is getting.

[cdc]

The ECU was bad when I got the car so it was replaced with a different ECU and the car was fine. Then the MAF went bad so I replaced it. I will check everything you guys say and see what I find out. I do know the ECU I put in was a different number than the one I took out I was told it would work the same.

[stealthee]

Do you have the part numbers handy for your original ECU and the one you put in?

[cdc]

I don't have the number from the old ECU (I think it was MD159963) I did not think I would need it, I have just checked the model number and it ends in 2D. I don't know what this means as far as the car being registered in Cali as federal spec don't have the EGR. I see a connector which I think is for the EGR so maybe I can do the resister mod to stop the ECU throwing the code but I will probably still fail the visual.

EDIT: or do I need a Federal spec ECU?

[stealthee]

I'm guessing your car is a 91-93. If thats the case its likely you dont even have an EGR. Even if you did you wouldn't throw a code.

Also 2D is not part of the part number. If you pull the actual part number off the ECU then we will know what the issue is. The 159963 is the Fed Spec number

[cdc]

The car is a 91, the 2D is the model number listed under the hood so from what someone said this makes the car a Fed spec car, I will have to check the ECU number as I have probably installed a Cali spec ECU.

[Steve '92ES]

First gen Cali spec DOHC had the EGR. Unfortunately my 92 ES is Cali and it has one. (it's also shown in my '91 manuals).
I'm currently running a fed spec ECU with no issues, it just ignores (doesn't have inputs/outputs for) the EGR. Going the other way around probably won't work though. A Cali ECU will be looking for the EGR and would trigger codes if it's not there.

The first thing to do is figure out what you've got. From the sounds of it you either have a Fed spec car and engine with a Cali spec ECU or, possibly, a TT ECU, which is just completely wrong and could explain some of the other codes your getting. Take a look at the ECU and post up the part number.

Once you find out what you've got you'll have to see what the rule is in Cali for inspecting a Fed spec. car. I'm sure there's a way to do it but I'm not familiar with Cali rules. Once you know that then you can figure out if it's easier to put in an EGR and make it Cali or swap the ECU and make it Fed.

[MaxClass]

You may want to verify this but if your getting 5 volts from the rear O2 sensor then it is a "Wide Band" sensor as was never originally installed in 19-93 cars. The 0.03 volts is more in line with a first generation OBD1 narrow band O2 sensors which only outputs between 0 and 1 volt.

Sound like someone installed the wrong one in the back.

[Steve '92ES]

You may want to verify this but if your getting 5 volts from the rear O2 sensor then it is a "Wide Band" sensor as was never originally installed in 19-93 cars.
What he's going to find is that 1st gen non-turbos don't have a rear O2 sensor. Not even Cali spec ones.
That's why he's seeing 5v, there's nothing connected to that pin to bring the voltage down. When I hook my datalogger up to the ES it still shows a sensor for the "rear O2" even though there's none there but it reads constant 5v. When I hook up to my TT both sensors read normally.
A 1st gen DOHC ECU won't trigger a rear O2 code. Since that's what he's getting I suspect he has the wrong ECU in there. Either that or Stealthee's right, the ECU is shot.

[stealthee]

A minor correction is that 1st gen NA's do not have a rear o2, but 94-95 NA Cali spec and all 96+ NA have 4 o2 sensors.

[Steve '92ES]

You are, of course, correct.
I've edited my post, and will say 5 Hail Stealthee's as penance... ;)

[stealthee]

Haha. I just wanted to post a clarification in case a 2g owner was confused as to what the extra o2s were in their car. :p

[cdc]

OK, I have checked the ISC and the resistance ranges between 28.7 to 29.7 so I think that is ok, I have checked the ECU number and it is 159962 and my old one I believe was 159963. So it looks like I have gone from a Federal ECU to a Cali one. I can understand the Cali ECU will throw a code for the EGR but would this cause other problems. I have reset the codes and I will see what comes back on.

Thanks for the help.

[stealthee]

Yeah thats a 91-92 ECU, but the fact remains you are getting codes that you should not get even with the Cali Spec ECU in a Fed Spec car.

[Gearhead]

Don't mean to hi-jack, but I have EGR on my 91TT. Does that mean my car is cali-spec or did all 1gs come with EGR?

[Steve '92ES]

On first generation cars:
All TTs came with EGR.
Only Cali spec DOHC non-turbos did. Fed spec did not.
You'll have to ask Stealthee about the SOHC...

You can tell if your car is Cali or Fed by looking at the last two digits of the model number on the plate on the driver's side firewall.

[stealthee]

I am sure the same works for 1g SOHC's in that only the Cali-specs came with an EGR.