98 z is sluggish

**phil85** · 04-05-2011, 02:19 PM

my 98 z is somtimes sluggish on take off and at lower rpm. barely will run but at 3000 and up comes alive and screams, this doesnt happen every time i drive it, only every so often. o2 codes come up somtimes. could it be the cats or the o2's or both?

**SSickLS1** · 04-05-2011, 02:29 PM

it can be both, try cleaning ur TB and MAF as well. are you running a gm o2 sensor or aftermarket?

**phil85** · 04-05-2011, 02:40 PM

i have no idea what they are, the original owner done some exhaust work so no idea, i cleaned the maf and it ran amazing for about 100 miles and started the same thing again,but not as bad

**TLS_Addict** · 04-05-2011, 02:42 PM

What filter does it have? Is it a K&N and have you oiled it lately?

Does the car stumble or just seem powerless at low RPMs?

**phil85** · 04-05-2011, 02:57 PM

k&n ive not drove enough to oil it less than 500 milesnand yes falls on its face at low rpm,then around 3k comes alive

**TLS_Addict** · 04-05-2011, 03:01 PM

Maybe the prior owner did and its cloggin up your MAF after you drive a bit? You said it runs well and then does it again.

**phil85** · 04-05-2011, 03:03 PM

yea,after a maf cleaning it runs great

**TLS_Addict** · 04-05-2011, 03:17 PM

I take it you just bought the car less than 500 miles ago?

I would clean the maf again and if it does it again you MAY have your answer.

**JayTA98** · 04-05-2011, 03:32 PM

Originally Posted by TLS_Addict

I take it you just bought the car less than 500 miles ago?

I would clean the maf again and if it does it again you MAY have your answer.

I will try that. Clean it again and see if it runs fine. If it does go ahead and replace the KN filter with a paper one. Is possible the filter was over oiled and its getting on the MAF.

**phil85** · 04-05-2011, 03:36 PM

i will do that, after looking i dont see any cats so i know they are not bad! could there be any other problems

**JayTA98** · 04-05-2011, 03:38 PM

Originally Posted by phil85

i will do that, after looking i dont see any cats so i know they are not bad! could there be any other problems

Did you reset the codes and the O2 sensors keep coming up?

**phil85** · 04-05-2011, 03:40 PM

yes, almost as soon as i clear them.

i see that as a problem,no cats but o2's

**JayTA98** · 04-05-2011, 03:52 PM

Originally Posted by phil85

yes, almost as soon as i clear them.

i see that as a problem,no cats but o2's

the car can be run without cats but if you have a bad O2 it will cause issues. How many miles in the car? Clean the MAF 1st and if the problem is gone then you know is the MAF getting oiled. If the problem is still there then maybe you have one or more bad O2 sensors. What codes are you getting?

If the previous owner did it right he should have tuned out the rear O2 sensors. Once you know which bank is the one giving issues you can try swaping the front sensor with a rear one. They are the same. If the problem is one of the sensors it will show a new O2 sensor code because you changed its location.

**phil85** · 04-05-2011, 03:57 PM

shows low voltage and a no activity code for bank 1 and 2

**JayTA98** · 04-05-2011, 04:04 PM

Originally Posted by phil85

shows low voltage and a no activity code for bank 1 and 2

Ok clean the MAF and if is still happening swap the O2 sensors if you have 4 in the exhaust. If you anly have 2 then they were removed and plugged. you will need to get new ones. Also check the wiring that goes to them. Make sure its not rubbing or melt against the exhaust. keep us posted.

**phil85** · 04-05-2011, 04:25 PM

i think it only has 2, ill run it up on the lift when i get home and see for sure.

thanks for the advice too! i'll keep you updated

**rsg98Z28** · 04-05-2011, 05:21 PM

it may not be getting power to the sensors, for some particular reason, definitely check for chaffed wires, or it could possibly be coincidentally two bad O2 sensors

**jwalters** · 04-07-2011, 04:34 AM

I second cleaning the TB and MAF, and its easy to do.

**Ls_won** · 04-08-2011, 11:29 AM

When i deleted my cats it ran like crap and when you got on it it came alive, i had frost tune my ecu and that fixed the problem. Also when you turn off those codes with what i assume you are using is a code reader, the computer still reads a code it just doesnt show up on your dash.