trouble codes 34 and 44 after these mods
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Joined: Oct 1999
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From: cincinnati,ohio,us
trouble codes 34 and 44 after these mods
i have trouble codes 34 maf sensor too low and 44 oxygen sensor lean after all the mods below. what could be causing this? my cat is broken up and rattling inside.
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CF,
Most of your modifications shouldn't be causing the DTCs. The heads, cam, filters, ignition, etc., won't affect teh actual measured air flow. Obviously, the TC, shocks, and cooling system mods won't be a problem. The one wild card is the HyperTech PROM. If you still have the original, I'd suggest reinstalling ot to diagnose the problem, then have a custom PROM burned for your setup. The HyperTech isn't going to be much more than a paperweight (mine is).
You'll need to measure the output voltage of the MAF to verify that it is working at all, or you can use scanner software to monitor the MAF flow reported to the ECM. You can check the output voltage at idle with a digital meter, and should get a fairly constant reading around .750 VDC:
The ECM relies on the TPS to calculate the allowable range of MAF signals. Make sure the TPS is correctly adjusted to 0.54VDC at the idle position.
You also need to be certain that the vacuum lines are connected correctly to all devices, and that there are no leaks in the intake system. This include the PCV ventilation system, so you need to be certain that all PCV air is drawn from the throttle body, not a breather cap.
Of course, any vacuum leak will contribute to a low MAF reading, and a lean condition (DTC 44).
You should also be sure that the AIR diverter is connected correctly, so that extra air is not injected into the exhaust, causing an artificial lean condition as measured by the O2 sensor.
Most of your modifications shouldn't be causing the DTCs. The heads, cam, filters, ignition, etc., won't affect teh actual measured air flow. Obviously, the TC, shocks, and cooling system mods won't be a problem. The one wild card is the HyperTech PROM. If you still have the original, I'd suggest reinstalling ot to diagnose the problem, then have a custom PROM burned for your setup. The HyperTech isn't going to be much more than a paperweight (mine is).
You'll need to measure the output voltage of the MAF to verify that it is working at all, or you can use scanner software to monitor the MAF flow reported to the ECM. You can check the output voltage at idle with a digital meter, and should get a fairly constant reading around .750 VDC:
The ECM relies on the TPS to calculate the allowable range of MAF signals. Make sure the TPS is correctly adjusted to 0.54VDC at the idle position.
You also need to be certain that the vacuum lines are connected correctly to all devices, and that there are no leaks in the intake system. This include the PCV ventilation system, so you need to be certain that all PCV air is drawn from the throttle body, not a breather cap.
Of course, any vacuum leak will contribute to a low MAF reading, and a lean condition (DTC 44).
You should also be sure that the AIR diverter is connected correctly, so that extra air is not injected into the exhaust, causing an artificial lean condition as measured by the O2 sensor.
Thread Starter
Member
Joined: Oct 1999
Posts: 113
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From: cincinnati,ohio,us
vader thanks for the good info. i believe the air divertor system is hooked up wrong do you have any diagrams of this or a pic that shows the hole passenger side from a top/side view?
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Joined: Oct 1999
Posts: 113
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From: cincinnati,ohio,us
the picture cuts off just where i need to see. maybe someone else has a pic. as for my tps voltage it is set at .062 volts at idle which it was at before my motor was removed and it ran fine at thsat setting.
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