1998 Honda Civic 1998 Civic RPMs drop off during accelerati

Tiny
BOARDER5384
  • MEMBER
  • 1998 HONDA CIVIC
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 164,000 MILES
When I get in the car to go i'll be accelerating fine, then out of nowhere im coasting. Rpms just start slowly dropping off and trans seems to hold gear. I keep giving throttle then finally under heavy throttle it downshifts and goes, already replaced plugs and wires, checked trans fluid, it was low but I added some, does not feel like it is slipping either. Only does this for the first couple minutes then is fine. Does not do it every time either. And sometimes out of nowhere on a trip it will do it just a little. Battery light flickers sometimes but does not seem related. Checked voltage seems to stay 14.2v also but have been unable to have meter hooked up when light flickers. Any ideas? Thanks
Wednesday, August 25th, 2010 AT 9:36 AM

7 Replies

Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Hi boarder5384,

Is the Check Engine Light indicating?

Did you check for bad ground circuits?
Was this
answer
helpful?
Yes
No
Thursday, August 26th, 2010 AT 2:24 PM
Tiny
BOARDER5384
  • MEMBER
  • 4 POSTS
Check engine light is on for low effecincy on cat convertor system, it has been for some time before this started. I was thinking maybe the tps?
Was this
answer
helpful?
Yes
No
Friday, August 27th, 2010 AT 1:17 PM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
What is/are the EXACT trouble code(s)?
Was this
answer
helpful?
Yes
No
Friday, August 27th, 2010 AT 1:25 PM
Tiny
BOARDER5384
  • MEMBER
  • 4 POSTS
P0171 sytstem too lean bank 1
p0133 02 sensor circuit slow response bank 1 sens 1
p0420 cat conv system efficiency below threshold bank 1
Was this
answer
helpful?
Yes
No
Friday, August 27th, 2010 AT 2:00 PM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
P0171 is most likely after effect of P0133 which is the most likely cause of the symptoms you are encountering. When thew O2 sensor fails, it can result in intermittent no throttle response.

P0420 is likely to be afaulty catalytic converter but it can also be due to P0133 so getting P0133 resolved should solve the problem of no throttle response and hopefully P0420 as well.
Was this
answer
helpful?
Yes
No
Saturday, August 28th, 2010 AT 12:28 PM
Tiny
BOARDER5384
  • MEMBER
  • 4 POSTS
Ok i'll give that a try then, how do I know which o2 sensor it is? And is it common for it to do what it's doing randomly? Because it'll do it for the first minute or so and then it's fine and sometimes it does not do it at all. Thanks
Was this
answer
helpful?
Yes
No
Sunday, August 29th, 2010 AT 9:43 AM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
The code indicates it is the O2 sensor before the catalytic converter.

Yes, a fault with the O2 sensor is known to cause intermittent no throttle response.

If you can get the freeze frame data, you might be able get an idea what has gone woong
Was this
answer
helpful?
Yes
No
Sunday, August 29th, 2010 AT 10:23 AM

Please login or register to post a reply.

Related Engine Revs Up Content

Idle Air Control Motor Replacement
GUIDE
Idle Air Control Motor Replacement
The idle air control motor or idle speed control motor is designed to adjust the air flow into the intake manifold at engine idle. Engine idle speed is monitored by the PCM...
VIEW MORE