Rennlist - Porsche Discussion Forums - 996 Forum

P1109 Error Code

karnuts — Fri, 01 May 2026 20:09:08 GMT

I got myself the iCarsoft POR 4 and when I ran diagnostics on my 2003 C4S, I got the P1109 error code. There is no CEL. I tried to clean the MAF with the MAF cleaner then reset it but it keeps coming back. I replaced the MAF with the Bosch unit and reset it, but it still giving me the error.

Should I worry about it as there is no CEL, the engine idle smooth.
Is the iCarsoft POR 4 giving me false code?
What other possible reason the engine developing the P1109 error code but no CEL

I am hoping that I don’t need to take to my indie shop for them to diagnose it.

Thanks

Coolant Tank Bleeder Valve

jdb1994 — Fri, 01 May 2026 19:48:54 GMT

Good afternoon afternoon everybody this is my first post as this is my first Porsche. I got a bit of a fixer upper, but it runs, I�m having some issues with coolant tank. Place that I bought it from said they replaced water pump and coolant tank, the coolant tank keeps overflowing through the bleeder valve. Today I took the time and dumped all, but about a gallon of coolant out of the car And replaced. I followed the guideline that I found on this forum For purging the coolant system of air. Everything was going good until the thermostat opened and then coolant started squirting out of the purge valve continuously until I shut the engine off. Am I missing something here or is this �supposedly�new tanks leader valve faulty? Thanks in advance. I�m sure they�ll be many more questions to come. I am handy with tools and have worked on other vehicles, but never a 911.

2001 911 Carrera 84,000 on body, 13,000 miles on a replaced motor, unfortunately I don�t have any information on the engine i.e. how many miles I had on it or if it was refurbished.

Lower door light operation not working correctly

dglenn99 — Fri, 01 May 2026 19:15:13 GMT

Forgive me for not remember what these lights are called (automatically light up for door open/close and auto shutoff after 30 seconds).

The problem:
The drivers side light doesn't work (I am waiting for the tools to remove fittings to check the bulb) and the Passenger light stays on the entire time the engine is started, driving around town, and remains on after it is parked for a period of time exceeding 20 minutes.

The passenger door light isn't that annoying during the day, but at night it makes it hard if not darn right impossible to see on turns, not to mention making it plainly difficult to drive at all at night due to it lighting up the interior. It's like driving with the drivers or cars overhead lights on.

Has anyone experienced this before? What did you have to do to correct the issue?

Optimizing gas consumption around town

dglenn99 — Fri, 01 May 2026 18:42:58 GMT

I have a Triptronic, so don't shoot.

My Trip shifts into 5th at 35mph and 1200 RPM, which is nowhere ideal to me and highly prone to lugging. Instead I use the manual option and use 4th gear to bring the RPM's up around 2000 at 35mph. Even there I shift it down to 3rd when going up a long hill.

Being a newbie to Porsche cars, I wanted to get feedback on what RPM range should I think of sustaining that won't lug the engine down and provide the better gas consumption at low speeds (25 - 45mph). I know it has to be wound tight to provide the best performance, but I have found little information optimizing the RPM range for just driving around town. With gas prices having risen so high again and trouble with either my O2 sensors or the Cat's killing my mileage (45mi per 1/4 tank), not the ideal environment for optimizing mileage, but this issue will be corrected before the end of the month. So now I just grit my teeth and my wallet open wide until then.

Nonetheless I am curious to see what feedback everyone has to offer. Everything is welcome except for 'suck it up, you bought the wrong car' type replies if you don't mind. I've always been able to eek out more mileage than the EPA numbers and magazine test results such as my 28mpg on the highway and around 23mpg driving around town in it prior to the CEL lighting up. So ignore my current CEL woes as a factor.

PSA - My 2000 Cab got T-Boned, it's at Copart

DSC800 — Fri, 01 May 2026 01:20:36 GMT

Just a quick public service announcement. Haven't been on the forum for a few months, or driving the car that much, but when I did - BOOM. No airbags or injuries though. Only the 2nd "real" accident in my 45 years of driving, but it was a sad one.
The "PSA" is for anyone wanting to buy this Cab for the engine & trans. The 3.4 runs exceptionally well, no bore-scoring when i checked bank 2 at time of purchase, running M1 5w50 changed every year, perfect filter, bank 1 pads & chain replaced, cam deviation at 1.9 and 1.0 degrees, water pump at 55k miles, EPS roller bearing installed in 2001. It didn't burn/leak a drop of oil between 3k mile oil changes. The trans worked exceptionally well, I felt I could row the gears at any speed and no syncro sounds. I doubt the accident caused any cracks in the engine/trans mount areas, but I wasn't able to check. It still runs and starts perfectly. It should be a great for someone with a 996.1 roller needing new power and other bits.

Unlikely I'll follow up on this post so good luck in advance to anyone who buys it. Very sad to see it gone.
https://www.copart.com/lot/50532276/...2-ca-san-diego

used parts available

jobyt — Thu, 30 Apr 2026 18:00:50 GMT

make offer, cleaning out garage. F&R discs available about half life left (27mm front, 23mm rear). LCAs and Camber arms in good shape, replaced with adjustable GT3 parts.

Trade: my 2014 981 Boxster, PDK for tiptronic Aerokit 996.1/.2 C2 or C4 Westcoast

keeeban — Wed, 29 Apr 2026 21:28:08 GMT

Hey all, as the title states i�m looking to trade my 2014 981 Boxster for a tiptronic aerokit 996.1 or 996.2 Carrera 2 or 4. I like to switch up the daily driver every year or so, so now it�s time!

Details:
WP0CA2A82ES121358
2014 Porsche Boxster
Black on black
PDK transmission
104,XXX miles (will slowly creep up as I still drive it)
Clean CA title in hand
Located in Santa Clara, CA

I am the 4th owner, purchased last year from San Diego, CA from the 3rd owner who purchased it in 2016 at 21k miles and had it until I purchased it in 2025 at 96k miles. The carfax is one of the cleanest I�ve ever seen. Maintained on the dot, mostly with Porsche, all documented. One minor on the carfax from 2019, cosmetic. Please see attached photos, link to the photo album, and the carfax.

Looking at recent sales for base 981 Boxsters (one being here on rennlist in February), these with my mileage, clean title, and good condition seem to be going for $25-26k.

What I�m looking to trade for:
-996.1 or 996.2 with aerokit
-OEM aerokit preferred, but aftermarket is fine as long as it was prepped and fitment is oem-like
-Tiptronic transmission (this will be my commuter, so one manual in my garage is enough for me)
-Any color, drivers quality is fine as long as paint presents well
-Clean, well maintained with service paperwork to back it up�replaced/upgraded IMS, RMS, AOS, borescope, transmission serviced, etc.
-Ideally a west coast car

I would not hesitate to drive my 981 Boxster across the country. It�s been very reliable and I had gotten nearly 40mpg driving back up from San Diego after I purchased it�was very pleasantly surprised. Compared it with a friend�s 2018 991.2 C2S and the 981�s transmission shifted identically to my friend�s car. Scuff on the front lower left bumper which is PPF�d, some paint cracks under the PPF, some front end chips from daily driving, but overall it presents very well. Interior 9/10, exterior 8/10.

What i�ve done since my ownership:
09/2025:

CHSTEK Headunit with backup camera (big thread on rennlist about this unit with tons of support and data)
Front tow hook cap, paint matched
Rennline phone mount
FCP Euro axle boot kit x2, engine air filter x2, cabin air filter x2, Liqui Moly 5w40 oil change kit
37mm lug bolts x10 (FCP Euro)
RSS 7mm front and 15mm rear spacers + extended lug bolts
Replace inner axle boot clamps x2

10/2025:

New Toyo Proxes sport AS tires @97,2XX
Frunk air filter, cabin air filter, engine air filters x2 changed at 97,830 miles
Oil change kit Liqui Moly 5w40 @ 99,016

04/2026:

Oil change kit Liqui Moly 5w40 @103,851

Full photo album:
https://photos.app.goo.gl/zFtBGE95i6az96Wd9

Blackstone Labs report

kaoddity1 — Wed, 29 Apr 2026 12:08:55 GMT

Egnine will go over 100k in the next couple weeks. I use Valvoline 5W-40. What could be causing this or is it of no concern?

"The viscosity is a little thin for 5W/40 again, but like last time, that's just something to note. The oil still did a
great job protecting wearing parts�see wear metals, which are trending at nice, relatively steady levels�and it 's not
thin due to fuel dilution. No other form of contamination is evident, either, and low insolubles show that oil filtration kept
up with demands. We quite like the trend that's developed over the last couple years. Good!"

SUS viscosity @210F levels for the last 3 years are 62.8, 64.8, and 64.7. Normal is 65-78.

Coilover checklist

Trip — Wed, 29 Apr 2026 10:22:55 GMT

I have a 40th AE and am planning to install Feal 441+ coilovers to lower the car about 1.5 inches. I have read mixed comments on here about whether lowering to this degree will induce bump steer, and whether I should get one of the aftermarket bump steer solutions like Elephant Racing or RSS (need for both front and rear?).

I�m also wondering whether I should get the Tarett drop links for the sway bars (again, front and rear?).

The car has 55k miles on it, so I�m considering what else I should do in terms of a refresh �while I�m in there.� I�m trying to keep this fairly budget friendly.

The car is a weekend toy and I plan to do a few autox events per year and maybe track day or two, but do not want to compromise street manners.

Any thoughts or opinions on this would be much appreciated.

Access to fuel delivery line

Drivelikeoldlady — Wed, 29 Apr 2026 05:02:00 GMT

I need to replace the fuel line that runs from the filter to the engine due to road damage. Does anyone know if this is accessible by lowering the engine (following Wayne Dempsey's book) to disconnect the line from the fuel rail and from the filter and just switching it out? Is there enough clearance to do this? Does the engine need removed fully? Thanks for any advice. It seems uncommon to need replaced by the shortage of info. on YouTube etc. about replacing fuel lines. From my experience of damaging it, If I were building a lifted off road 996 I would consider protecting the fuel lines as well as just the oil sump as seems common. Thanks

Shifter issues after replacing transmission mount.

MB TREE — Wed, 29 Apr 2026 00:29:29 GMT

Hello everyone, I have a '04 911 996.2 6 speed. I just changed out my transmission mount. After finishing up I took a ride and noticed having issues shifting into 1st and 2nd. Do uguys think this is because of replacement of the mount? If so, can anyone help me out with adjustments to the cables, or whatever I need to do.
Any info would be appreciated.
Thanks,
MB.

Part Number Please

SSDVC — Tue, 28 Apr 2026 21:25:52 GMT

Does anyone know the correct part number for this plastic twist pin for the trim in the frunk? I need a few of them, or a bag, because I keep losing the little buggers !! Thanks !

Pesky ABS 4340 Error

Capt RonG — Tue, 28 Apr 2026 17:05:07 GMT

2001 Carrerra 4, w/ Tip

I've been chasing a P4340 "Brake Switch a" error for a long time now. As you can see from the picture, I have the interior ripped out so I can access and inspect all the wires. Both brake switch circuits appear to be working at the DME according to a scanner. The actual brake light circuit (Brake Switch 1) also correctly reads out at the ABS unit. But, on the scanner, the brake pedal shows as not actuated. The brake pressure signal changes when I press the pedal.

With the ignition off, I removed the brake switch, and connected the normally-open side (Switch 1) and normally closed sides through a 10 ohm resistor and 20 Ohm resistor to ground, respectively.

I removed connector X2/4, and measured 10 Ohms (Switch 1) to ground on pin 4. That's good, but just verifies what the DME was already telling me..
I removed connector X2/5, and measured 20 Ohms (Switch 2) to ground on pin 20. " " "

I measured 10 Ohms at Pin 14 of the ABS connector (Switch 1), which verifies what the scanner says. Switch 2 doesn't appear to go to the ABs on the schematic.

I believe the PSM connector is the white one near the ABS in the luggage compartment. I haven't had as much luck verifying the signals to the PSM and I'm not 100% sure I have the right connector. It's supposed to have both switch signals, but I only see the black and orange Stop 1 signal going to it.

But, I'm also wondering if the brake pedal value int he ABS is derived from something other than the switch - like a pressure threshold or some such. Any ideas?

Engine overheating

dglenn99 — Tue, 28 Apr 2026 16:03:04 GMT

In another thread I started recently to identify an unknown reservoir in the engine compartment, among other things it was mentioned that water pockets could have been the culprit requiring me to add another 2 quarts to get the coolant up to the proper level.

Yesterday my engine temperature suddenly began to quickly rise right after I had turned on the heater to eliminate a possible source of water pockets (mentioned in another thread I had started), so it happened I was watching the temperature gauge closely at the time. I was in town, only doing 35 mph. Fortunately I was close to home and immediately turned around and kept a close on the gauge. I arrived in the garage without the temperature rising much over 200. I looked for leaks (none), checked the coolant level (good) and pressure when removing the fill cap. The engine didn't have any unusual noises and sounded normal. The radiator had been recently serviced, topped up yesterday and the serpentine belt had been replaced and a sundry list of other items not related to this issue weeks earlier

I had just left the house, engine was cold, and it usually hits operating temp after about a half mile after starting up. I see two possible issues:

1) Radiator low speed fan(s) resisters had failed. The previous night it happened to be raining hard with the temps in the mid-60's. It was possible one of the resistors was hot and the internals broke after being struck by the water. So replacing the failed transistor will resolve the issue. Best to replace all of them at once than piecemeal, after all they are the original parts and resistors do deteriorate over time.

2) Thermostat isn't opening properly. Here replacing the thermostat and water pump as an added precaution (since it has to come out to replace the thermostat) since I don't know how old it is and when it was last replaced.

Can anyone else think of any more possible areas that might pose a problem? I can test the resistors, I can't test the thermostat (that I'm aware of), and I don't want to go through that expense only to discover there is another issue that is the root cause.

Thank you all in advance. I'm a virgin in the Porsche scene and I'm not yet familiar enough with all the foibles to watch for. My mechanic apprentice days were years ago working on MG's and Triumphs.

AGA Transmission Mount Tool For Sale (or Rent)

bones519 — Tue, 28 Apr 2026 15:29:02 GMT

Have an AGA Transmission Mount Tool for sale (or rent). Purchased earlier this year and used once. Good condition with some tool marks on the nuts and cylinder cap. Otherwise like new. Rennlist Marketplace listing here: https://rennlist.com/forums/market/1511028 (which just takes you to the Ebay listing, but trying to abide by the rules!)

If you�d like to rent, please message me. Thanks.