I just checked my car today to see what kind of gas mileage I was getting ( I already knew it was bad, just didnt know how bad) Im gettin 7miles to the gallon right now. Thats being driven in town 90% of the time, but it shouldnt be that bad. What the **** could be wrong it?? Help please!

 

What kind of car? Year, model, engine?

 

That would be really bad for a Honda.

 

haha, ya that might be helpfull if you knew the car huh? It a 1996 Z28, 5.7

 

How is the car running? Rich, erratic, is there a check engine light?

 

It seems to be running fine, i dont notice anything that sounds or feels different. I have taken the car into a local repair shop and i didnt have a check engine bulb in my dash. So they said that it might be the reason why because without that bulb it messes up the computer and some kind of relay. So they put in a bulb and thought that might fix it. But now im in the same boat i was in before i took it there.

 

Having a burnt out or non-existent bulb in the gauge cluster is not going to affect the PCM or how the car runs for that matter. If they came to the conclusion that the light was burned out, did they at least hook up a scanner to see if there were any current or past trouble codes?

 

Ya they ran a diagnostics on it and it showed that there wasnt a bulb in the check engine spot, they said that because there wasnt a bulb in there that my car was in a "limp" mode, which effected the way it idled. So they put the bulb in, and after that i believe the diagnostics showed there werent any other problems.

 

Nice, easy fix.

 

They did put a new bulb in, i think what i said might have been misleading. The bulb didnt fix the problem, im still getting 7 miles to the gallon.

 

You need to put a scan tool on it and see what the O2 sensors are doing.

 

There are so many things that can affect mileage; everything from tire pressure to driving style.

if the scan comes back clean I'd look at the usual suspects first, air and fuel filters, plugs, wires, those sorts of things

 

Go to the "User CP" button on the red bar at the top of each page. Use the "signature" field to add the basic info about your car - year, model, engine, trans and any major mods. That way, people won't have to ask for more info in order to help you.
I'll repeat what has already been said. The missing SES bulb was NOT affecting the PCM and making it run poorly. It would NOT put the PCM in "limp" mode. Someone is feeding you a line of BS. The scanner would have read the codes for problems, whether the SES light had a bulb in it or not.

Poor fuel mileage often results from a "false" lean condition. The O2 sensors see air in the exhaust, assume the engine is running lean, and start adding fuel the engine doesn't need. Leaks in the exhaust before the O2 sensors, heavy misfires, or defective O2 sensors can cause a "false" lean. Maybe you have an exhaust valve hanging open, and theres intake air blowing through and making the O2 sensor think its a lean exhaust.

May also be badly leaking injectors. Could be a defective fuel pressure regulator that is causing the fuel pressure to be excessively high. Could be leaks in the fuel system. Could be a badly plugged catalytic converter, but that would kill the engine's power.

 

If they tell you the johnson rod is bad i would find a new mechanic. Maybe you should anyways.

 

alright guys, thanks for everything u have provided me with so far. But i just discovered something pretty strange. I filled my car up, and on that full tank i drove nothing but highway miles. I did this because the last time i checked it, it was all city miles. So i wanted to see what i was getting on the highway. And amazingly i was gettin nearly 22 miles to the gallon on the highway! I really dont understand that at all.