Joseph Caruso

I just bought this 2004 911 Turbo and I'm having a hard time passing the inspection. I changed the Vent valve on the tank and also checked the fuse. It runs fine after I reset the code but after a 50 miles. Or more the check engine light comes on again. Only two monitors don't complete. Catalysts system and evap system monitor says inc. It's also hard to start after I turn it off. Cranks but don't start right away but then it does after a little. Runs very strong otherwise. Ant suggestions? Joe

jhbrennan

Is it just the "not ready" monitors that are causing the fail? If so, have you tried the Drive Cycle to reset the monitors. Search - it's well-documented...but it can be a tedious process. Where are you located?

"02996ttx50

while the two monitors ( evap & cats ) staying in "not ready" mode seem to be the most problematic, when re-setting you'll need to determine the cause of the cels. here in CA you cannot have had "recent" cels let alone any active cels in order to pass a smog test.

irrespective of the code you have you'll need to both "drive cycle "reset" as jhbrennan suggests but also have driven long enough ( 100 miles min? ) in order the obd reader at the smog tester doesn't show a "recently" cleared cel. if your car is difficult to start and keeps throwing cels, then presumably you have issues that probably need to be resolved before you pass smog. but thats just a "guess".

the whole thing can be a daunting process. in case you don't know it, here's the BMW drive cycle reset protocol which is the same for our cars. sometimes it works? and sometimes it leaves the ( evap and cats ) still "not ready" as has recently happened to me.

do you know/remember the reset protocol? it's a pita but try it first, is what i would do.

here it is: follow it to the letter or it will not work.

Start engine, let idle for approx. 2 min, 10 secs.

Accelerate to 20-30 MPH, Maintain steady speed for approx 3 min, 15 secs.

Accelerate to 40-60 MPH, Maintain steady speed for approx 15 mins.

Decelerate and come to a stop. Then:

Idle in Neutral for 5 mins. (manual trans.)

During the drive cycle, do not exceed 3,000 rpm or 60 mph.

"02996ttx50

oh, yeah. could be as simple as a bad gas cap seal also....

fpb111

Hard starting coupled with P0446 is most often the Evap Purge Valve in the engine bay.

fpb111

Check out this thread for some clues.
https://rennlist.com/forums/996-turb...-question.html

Joseph Caruso

Hi, I'm located in New York. I haven't tried The Drive cycle yet but I will. I changed the Vent Valve and New Cap and gasket. Cheched the fuse E6 then I also checked them all. I can clear the code then drive it hoping it will reset the evap and catalyst monitors but at like 70 miles it trips the check engine lite. I'm thinking the Vent valve in the engine compartment is next. Thank you for your help and I'll let you know how I make out. Joe




Is it just the "not ready" monitors that are causing the fail? If so, have you tried the Drive Cycle to reset the monitors. Search - it's well-documented...but it can be a tedious process. Where are you located?[/QUOTE]

Joseph Caruso

Ok, I recieved the Purge Valve for the fuel vapor canister 996-605-201-oem . So i go out to my car thinking I'm gonna just install it. I have no idea where it is and i can't even fit my hands on top of the engine! LoL Does anyone have a location chart . Im guessing its on top of the engine and I'm looking online and i haven't found one video how to install or location. Im just trying to change one valve until i fix the problem. Im just thinking i might want to change the other valves while I'm doing it? Anyone have any advice for me? is it just raising the rear of the car to get access to top of the engine? I appreciate all the help on this site, You guys are awesome! Joe





Thank you I'm trying that next. Joe

Freddie Two Bs

Don't expect the textbook drive cycle to work.

Unless Porsches are very special cars in that regard, you'll most likely have to take it to the track to lose the "not ready".

Happened to me with two non-porsche cars. In both cases I followed the instructions religiously for over a thousand miles, to no avail. For both cars the problem disappeared after a track weekend. The kind of acceleration, deceleration and sustained speed driving truly required to complete a cycle is almost impossible to execute on the street.

jhbrennan

As posted previously, the Drive Cycle calls for a couple of circuits where you aren't supposed to exceed 3000 rpm and 60 mph - hard to do that at the track. Follow the cycle...the track won't set the monitors to ready. There are other versions of the drive cycle but this one has worked for me on 2004 996 40th AE.

A complete driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in under fifteen minutes. Some "logged" codes require 5-8 complete drive cycles before they will reset (and can't be reset easily via the OBD2 port).

To perform an OBDII Driving cycle do the following:

Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.
Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.
Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.
Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.
Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.
Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.
Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.
Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.

"02996ttx50

there is no way that drive cycle will work exceeding 3k rpm or 60 mph. just no way. for many it works on the first try and has for me. last time took 600 miles but that is because i had no place to properly fulfill the "cycle" protocol to the letter.

it is sequential and not random.

Joseph Caruso

Ok, I recieved the Purge Valve for the fuel vapor canister 996-605-201-oem . So i go out to my car thinking I'm gonna just install it. I have no idea where it is and i can't even fit my hands on top of the engine! LoL Does anyone have a location chart . Im guessing its on top of the engine and I'm looking online and i haven't found one video how to install or location. Im just trying to change one valve until i fix the problem. Im just thinking i might want to change the other valves while I'm doing it? Anyone have any advice for me? is it just raising the rear of the car to get access to top of the engine? I appreciate all the help on this site, You guys are awesome! Joe

911mhawk

You need this link:
http://www.porsche.com/all/media/pdf...SA_KATALOG.pdf

Google the Porsche part number dude:
https://www.google.com/search?q=996-...w=1216&bih=705

Joseph Caruso

Thank you Hawk! I need that and its a lot of info! I'm gonna hunt that valve down and change it out! I see theres another valve right in the same housing. It looks like theres 2 cut off valves. one in the valve housing and one in the carbon canister? Im sure its a good idea to replace all of them while I'm in there? Thanks again, I would have never found it unless i had that pic..... Joe

powdrhound

I have all the valves in the front right fender if you need those. To change the purge valve in the engine compartment you simply need to drop the engine a couple of inches. I did this a few weeks ago. There is no way to reach this without a drop.