3.4 motor swap in a 1998 Boxster

[Reebuck1]

Ahsai/ Loren,

 

Finally got the motor in the car and started it up today....major mile stone.

I had my DME re-flashed with a ROW flash.  Am running CAT by pass pipes with no muffler as of yet.

Put the boxster 2.5 pre-CAT oxygen sensors on the by-pass pipes.

No seats in car yet.

Motor started right up...at idle ...NO FAULTS !!!

blipped the throttle a few times and got the following FAULT CODES:

P1319

P1318

P1317

P0300

P0306

P0305

P0304

P0150

 

I am only guessing......... I have a bad Oxygen sensor in bank 2 (4,5,6)

 

Cleared faults...and again at idle, it caused no fault code.   gave it some revs. and same codes as above showed up. 

 

Any thoughts?

 

Pictures and writ-up to follow.

 

Thanks,   Bob

[Loren]

You have misfires on cylinder 4, 5 and 6. Until you find the cause of those your will likely have more (false) sensor faults.

 

Which DME 5.22 or 7.2?

Which intake and throttle body(Boxster or Carrera)?

[Reebuck1]

DME is 5.2.2 from the 2.5 Boxster

 

Intake and throttle body is from the 996 Carrera

 

Air filter box is from a 987 but converted to fit in the 986

 

3 1/2 inch silicon piping runs from air filter to throttle body

 

MAF is stock from the 996 with the 3 inch 987 tub that holds the 996 MAF

 

MAF is located approximately 6 inches from the throttle body opening.

 

oxygen sensors are the stock 2.5 oxygen sensors

 

[Reebuck1]

Still am wondering why I get no fault codes when car is just idling but as soon as I blip the gas I get a check engine light and the above fault codes?

[Ahsai]

Maybe you can plot the pre-cat O2 sensor voltage on both banks and see how they look? They should swing between 0.2-0.7v at about once a second at idle.

[Reebuck1]

• Thanks guys for the response...I have to go out of town for a few days and will be back at it shortly.   I'll report back with pictures.  Again Thanks !!

[Guest]

Do u fix it yet?

I remember that I had to play with different value resistors attached in line with the MAF to eliminate some of this errors. Had to use the Durametric to get it right - basically to compensate for a different size intake from what the computer expected - the brain was a 996 original for the 3.6

[Reebuck1]

Don't have it fixed yet.   Still getting data and will post pictures and charts shortly.    Thanks

[AufDuetsch]

I am curious as to why you didn't do the 3.6 swap like Tholyoak??  Also, is Tholyoak still around and does he do swaps for cash????  Oh, by the way, I am new to the 986 forum, but I have had by 986 for over a year and love it.  Its just a stock 2.5 with a shift kit (TIP) and it is the funnest car I have ever driven....I laugh every time I get on the highway and drive from Long Beach to Downtown LA.....weeeeeee all the way down the 110.......I wreck this thing occasionally and rebuild it and it just comes back better than before....going to get it out of the shop, and I can't wait.......Hoping to do a big motor swap....Does anybody know if you can drop a 3.8 in a 1998 and use the standard 5 speed tiptronic????????  Thanks for any input.....I really proud to be a member of the 986 Forum.....

 

Auf Duetsch

[JFP in PA]

I am curious as to why you didn't do the 3.6 swap like Tholyoak??  Also, is Tholyoak still around and does he do swaps for cash????  Oh, by the way, I am new to the 986 forum, but I have had by 986 for over a year and love it.  Its just a stock 2.5 with a shift kit (TIP) and it is the funnest car I have ever driven....I laugh every time I get on the highway and drive from Long Beach to Downtown LA.....weeeeeee all the way down the 110.......I wreck this thing occasionally and rebuild it and it just comes back better than before....going to get it out of the shop, and I can't wait.......Hoping to do a big motor swap....Does anybody know if you can drop a 3.8 in a 1998 and use the standard 5 speed tiptronic????????  Thanks for any input.....I really proud to be a member of the 986 Forum.....

 

Auf Duetsch

 

First, welcome to RennTech :welcome:

 

I believe you will find that Todd relocated to Canada some time ago.

 

With enough time, money, and welding equipment; you can put just about anything in there.  We had a customer doing a 996 Turbo engine transplant into a 986.  Long before he was even close to being running, he had spent more than a new Turbo car costs.

 

It all depends upon where your head is at..................

[AufDuetsch]

Thanks for the welcome JFP....I love my car and really enjoy tinkering with it.  I had no idea when I bought it how fun it would be...I am aware that money will buy you almost anything, but I don't waste money...I do the little things on my car and have my mechanic buddy help me with engine works.  We will be upgrading this motor to a 3.6 or 3.8 and won't be breaking the bank...we already have a 3.6 and 3.8 ready to go....I am just trying to figure out what I am gonna drive for fun when the car is getting upgraded.....I think you could put a TT in these cars, but I am not about to lose my trunk space like some guys do...That is where I put my pizza to keep it warm when I get a thin crust to take home.  I hope to see Tholyoak around, I love reading his swap postings.  I have learned a lot from them...I guess its about time to pull out the ole 2.5.  I plan on rebuilding it and keeping it well preserved for future transfer back into the car if so desired.  You never know what people will want to buy in the future.  2.5s that nobody wants now may be all the rage when one of my kids has this old Boxster.....plus, the PCA events with the 2.5s are very interesting and very challenging for the drivers of these cars.  I learn something new every time I go out to the track.  I will be glad when our new 53 acre Porsche Center will be ready here in LA County in the city of Carson.  It will have 7 premo tracks for working on driving skills....I hope to see you out there when it gets finished later on this year.  again thank you for the warm welcome.  I will see you out on the track, hopefully, soon

 

KK