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Matt
Matt, Engineer
Category: Ford
Satisfied Customers: 21995
Experience:  BEng hons Mech engineering, in auto industry 22 years
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I recently bought a 95 gt that has had several mods done to

Customer Question

Hello, i recently bought a 95 gt that has had several mods done to it. I am having a few issues i want to fix if possible? My Gas milage is horrible @ 120 miles to a full tank of high test. I renently changed my staock MAF and housing to a BBK which ran like crap. I changed back to my OEM and now the car will nor stay running while it is plugged in. I ran an OBD1 scan and recieved a few codes. The ones i dont understand are a EGR flowrate issue as well as the car is in limp mode according to the scan code? The car runs very strong at WOT but horriable at low RPMs? I renently changed the AIC and the VSS sensor b/c the speedo/ odometer quit working. VSS swap did not fix the speedo problem. Dont know if there is a ground issue somewhere as i am having alot of electronic issues at once? 2 window motors quit, left side headlight is half as dim as pass side. Any help would be greatful? Im not a mechanical person but have some basic understanding. Thanks Rob
Submitted: 2 months ago.
Category: Ford
Customer: replied 2 months ago.
Car will only run with the MAF unplugged. Recently i was able to get it running with the MAF plugged in but when any gas is applied it boggs down which i assume is too much gas?
Customer: replied 2 months ago.
Here are the codes i recieved,
KOEO. 157, 452,
KOER. 172, HEGO (HO2S) sensor fault/Lean
332, Insufficient EGR flow detected
632, overdrive transmission cancel switch/ no action during aelf engine run test998, Operating in Failure mode
Expert:  Matt replied 2 months ago.

Hello Rob

those faults point to a lean fuel mixture which would explain the lack of power and that fact it runs OK at high rpm means the fuel pressure is probably OK so its probably the exhaust O2 sensor giving issues as that has a strong effect on fuel mixture at low load

however as you have a host of different issues I'd agree to 1st check the condition of the main battery connections and the engine earth connection, also pull the high power fuses in the engine bay fusebox and clean them too and check for cracks

also use a meter on the battery to check that you have at least 12V with the engine off and that it increases in voltage with the engine running

if this is all OK then check the condition of the exhaust sensor connections and the wiring for damage and if this is OK consider replacing the sensor

I'd also check for an airleak after the airflow meter, any air dragged in here isn't 'seen' by the ECU and so not compensated for and can lean the engine out and can also allow the engine to rev up when not desired causing rough running.

As its a mechanical fault it tends not to turn on the fault light and you can sometimes hear a 'hissing' noise with the engine running.

Check the hose clips for tightness and inspect the trunking for any cracks or splits and also all the vacuum system, the small bore pipes and fittings for cracks and missing parts.

The best way to locate a leak is to have the engine running and warm and then spray lighter gas /propane or brake cleaner around each joint in turn. If the engine rev's up you've found your leak.
Now you might think that spraying lighter gas around a hot engine isn’t wise, however the flash /ignition point of gas is about 400°C so you need a naked flame or spark to set it off and I’ve used this method for many years without incident.
Work your way through each possible joint one at a time and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to provide a spraying 'wand' and allow a direct blast of gas into each area, especially those difficult to reach with large implements.

Air leaks are very temperature dependent as gaps can open up as things expand with temperature so depending on how the leak occurs ( on a hose joint with a clamp expansion will help seal and on a vacuum hose expansion ill make a leak worse) so leaks can be better or worse as the engine heats up.

Expert:  Matt replied 2 months ago.

Hi
do you still need help?
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