Help!!! Acceleration lag or bog problems with 98 Boxster - 986 Forum

cbarnes · 10-05-2010, 06:18 PM

I have a 98 boxster and had the check engine light come on. Was told I needed a new passenger side cat. so, instead of paying $900 or more for one. I decided to buy two new cats from Fabspeed. After in stall the check engine light came off. I had a lag in acceleration before I replaced the pipes and after. It mainly does it when in automatic mode. When I use the tiptronic it seems to not do it. Does anyone have any idea of what could be causing this or what it could be???

Also, I have a problem with my spark plugs seals or rings leaking. I replace plugs, seals, and o-rings and cleaned everything up nicely. Now its still leaking and a little more than before. I assume its because of being cleaned.

Any advice or help would be greatly appreciated.

Thanks in advance.

Topless · 10-06-2010, 07:39 AM

First things first.
98 Boxster Tip, mileage? Any other work done recently? Fresh fluids in engine and trans? CEL on? What error codes are you getting?

cbarnes · 10-06-2010, 06:10 PM

Quote:

Originally Posted by Topless

First things first.
98 Boxster Tip, mileage? Any other work done recently? Fresh fluids in engine and trans? CEL on? What error codes are you getting?

It has 89,800 miles. The other work done was new oil change and filter, water pump and coolant, new right side passenger cv boot, new belt and cleaned the cold air intake and mass air flow sensor.

I did find out that the plugs are not leaking the seal from putting on the cv boot without a new seal is leaking so, going to fix that.

I was going to change the trans fluid and differential today at a shop but they advised against it. Since they didn't know if it would make the lag worst. Lag only happens during drive not in tiptronic. Not sure its a trans issue. No cel light on and no error codes when last checked. The transmission fluid leaking a little from the seal looks clean and may have been done not to long ago. I just bought the car and have put about 1k miles on it and was aware of needing to do the 90k service and other things. except the lag bc thought it was the cats.

Hope that helps.

Thanks!

Topless · 10-06-2010, 06:36 PM

"cleaned the cold air intake and mass air flow sensor."

Ding ding ding ding! Any check engine light error codes?

It is very common for an aftermarket "oiled" filter to foul the MAF causing the car to run lousy. Many owners have reverted to a paper filter with a fresh new MAF and restored all performance to their car.

Mauiboxster · 10-06-2010, 06:54 PM

To make sure it is the MAF you can drive the car without the MAF in at all and if it is improved than you will need a new one. Same thing happened to me after cleaning MAF. I have never met anyone that has cleaned the MAF and still was able to use it. Just try what I said and if it run right than get a new one.

cbarnes · 10-06-2010, 07:01 PM

Quote:

Originally Posted by Topless

"cleaned the cold air intake and mass air flow sensor."

Ding ding ding ding! Any check engine light error codes?

It is very common for an aftermarket "oiled" filter to foul the MAF causing the car to run lousy. Many owners have reverted to a paper filter with a fresh new MAF and restored all performance to their car.

The car had the cold air intake when I bought it. I didn't actually touch the filter. Just sprayed some crc mass air flow on the air flow sensor.

So where is the best place to buy the parts to revert it back to paper and how much is these parts and the maf?

Thanks

cbarnes · 10-06-2010, 07:48 PM

Quote:

Originally Posted by Mauiboxster

To make sure it is the MAF you can drive the car without the MAF in at all and if it is improved than you will need a new one. Same thing happened to me after cleaning MAF. I have never met anyone that has cleaned the MAF and still was able to use it. Just try what I said and if it run right than get a new one.

No check engine light on. I will try this before I order anything. If need to order the mass air flow sensor and paper filter is there anything else I would need to order with it? looks like ******************************** and pelican parts have them the cheapest.

I don't have old parts for this so don't know if I need anything for the paper filter to go in.

Thanks

harryrcb · 10-07-2010, 06:45 AM

You will need the air filter box that also houses the MAF, you can look on ebay to see if you can find a used one, new they are about 400 and a son of a gun to put in, you will need to remove your left intake manifold to get it in there. you will also need intake manifold seals. but before you do all that. take you air filter off, clean you maf or remove the wire and drive it (not on dirt road) to see if your lag is gone. If no lag then plug your maf back in, check again. if no lag, clean you air filter thoroughly and spray on the oil but check how to do that properly on line. I have had an cold air filter on for over 2 years without any problems.

Fluellen · 10-07-2010, 11:18 AM

The OP states that the lag only happens when the tip is in auto mode. It does not happen when the tip is in manual mode. At least that is how I interpret the OP's posts.

If that is true, it does not seem that the MAF would be a likely culprit here.

Topless · 10-07-2010, 11:25 AM

Quote:

Originally Posted by Fluellen

The OP states that the lag only happens when the tip is in auto mode. It does not happen when the tip is in manual mode. At least that is how I interpret the OP's posts.

If that is true, it does not seem that the MAF would be a likely culprit here.

I don't know. When my MAF was fouled it only noticeably lagged in 3rd gear under load. Once I replaced it the whole car felt better. Before changing any parts I would get this car on a scan tool, read the error codes and do a proper diagnosis. Anything else is just a shot in the dark.

harryrcb · 10-07-2010, 01:09 PM

Quote:

Originally Posted by Fluellen

The OP states that the lag only happens when the tip is in auto mode. It does not happen when the tip is in manual mode. At least that is how I interpret the OP's posts.

If that is true, it does not seem that the MAF would be a likely culprit here.

I guess I missed that, hmmm that is a strange one.maybe it's driver error? Heck sounds like a vacuum problem or the computer is on the blitz. Not my field of expertise.

cbarnes · 10-07-2010, 07:10 PM

Quote:

Originally Posted by Topless

I don't know. When my MAF was fouled it only noticeably lagged in 3rd gear under load. Once I replaced it the whole car felt better. Before changing any parts I would get this car on a scan tool, read the error codes and do a proper diagnosis. Anything else is just a shot in the dark.

It does only happen when using the automatic mode and it's around 3rd gear and 3,000 rpm or so. However, I did unplug the battery for a while and then drove it and it seemed to be working fine. Have to wait and drive it tomorrow again and see if what happens. Someone told me to do that to clear the old maps.

Last time I had on scan tool everything came up fine. Will have checked again.

Thanks!