oxygen sensor???

gebasgt

New Member
Jul 5, 2003
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My 93 cobra sometimes seems to lag or seems to not respond very well when WOT. Sometime I'll pull strong up to 3500 RPM o so then the power drops off for a second or so then kicks back in and pulls strong. I can't figure out whats causing this. Could it be an oxygen sensor gone bad and its dumping too much fuel? I do know that my car runs rich. Any help would be greatly apprecited. Also have new plugs, rotor and cap and timing set to 14 degrees running 93 octane.
 
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nope, the EEC ignores and doesnt use o2 feedback in WOT mode.

the o2s are used for normal closed loop driving and idling. so an o2 problem will only cause problems when the car is in closed loop (up to temp idling and cruising) and wont cause WOT problems. cold starts dont use the o2s either.
 
nope, the EEC ignores and doesnt use o2 feedback in WOT mode.

the o2s are used for normal closed loop driving and idling. so an o2 problem will only cause problems when the car is in closed loop (up to temp idling and cruising) and wont cause WOT problems. cold starts dont use the o2s either.

Any suggestions then?
 
Even though O2s feedback is not used in open loop, bad O2s will affect the corrections learned by the adaptive strategy (updated during close loop operation) the system applies to the open loop calibration tables. Suggest to run the DIY KOEO/KOER self tests to obtain the failure codes that could be causing the problem. LUK
 
Try unpluging the o2 sensors (do this only if you can the check engine light that will come on when you do this) the car will run a little rick but if the problem stops you will know its the o2 sensors. I had the same problem with my jeep. See if that works. I'm not sure about the WOT operation so foxfan might be right.
 
Funny you mention this issue I just posted a thread similar to this. My 93 cobra has the same issue. I removed the under drive pulleys thinking it might be related, but it wasn't. I re-ran the white trigger wire on my MSD ignition since the tech told me this could be an issue. Still no change. I'm now looking at the MAF and Throttle body but need inputs before changing them out.
 
Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

See http://www.troublecodes.net/Ford/

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If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

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89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.

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Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see http://www.midwayautosupply.com/pc-7208-90-equus-digital-ford-code-reader-3145.aspx – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.