Need HELP...Running BADLY.

[IwantaSVX]

Ok, I've been having some issues with my '94 LSi. Up until now I have been getting an occasional CEL light which was very occasional. I ran the codes before and got a code 32 (RH O2 Sensor). I use to get upwards of 330 miles to a tank of gas (city driving). I put 15K miles on the car since June. Parked it for about 2 months. Now I have been driving it and its been getting worse like everytime I fill the tank up with the last tank getting 240 miles. This tank is at like 134 miles and its on 1/4. SVX fuel gauges are not known to be accurate but mine always has been and I know its a lot more gas. I usually fill it up at the same point.

Well, tonight I was coming home from a 30 mile round trip. I thought my tranny went again because I was going up a hill and I gave it gas to kick it into 2nd and it was acting like it ran out of gas. It kept doing this and eventually was hesitating like this on level ground. The CEL came on and stayed on until I got home and parked it in the garage. I gave it gas to see how the engine sounded and it was still holding back like it didn't want to rev much past 3K.

Pulled the codes:

21: Coolant Temperature Sensor or Circuit
23: Air Flow Meter or Circuit (Exc. Justy)
32: Oxygen Sensor or Circuit (No. 1, Right Side, On SVX)
37: Oxygen Sensor (No. 2, Left Side, On SVX)
56: 56 EGR System

Now, I put a new Coolant Temp Sensor in back in August. I'm hoping for some input from someone who might know what is going on or can give me an idea of where to look.

[Aredubjay]

Did you replace the O2 sensors when you got the first CE Light? If not, that's your first order of business. If that doesn't take care of it, it's likely your MAF sensor.

Yours is behaving just like mine did when the MAF sensor went. However, I'd do the O2's first, to see if it takes care of the problem.

Sometimes, the O2's being out will cause signals to trip "downline."

But, that's just MY opinion.

[IwantaSVX]

No, I did not replace either o2 sensor when the light started coming on. It was so random and there was no change in the cars performace or gas mileage at first....I saw no reason. It didn't start getting poor mileage until after it sat. I really thought it might have been a loose connection because the CEL was so random. I thought if either o2 were bad or reading out of range it would set the CEL and stay lit.

The car seems to be running fine now. Its odd. It was acting like it was out of gas before but it smelled like it was running rich. It idles fine and from what I'm reading the MAF would affect the idle. So...I think I will try both 02 sensors.

[Aredubjay]

Originally posted by IwantaSVX
No, I did not replace either o2 sensor when the light started coming on. It was so random and there was no change in the cars performace or gas mileage at first....I saw no reason. It didn't start getting poor mileage until after it sat. I really thought it might have been a loose connection because the CEL was so random. I thought if either o2 were bad or reading out of range it would set the CEL and stay lit.

The car seems to be running fine now. Its odd. It was acting like it was out of gas before but it smelled like it was running rich. It idles fine and from what I'm reading the MAF would affect the idle. So...I think I will try both 02 sensors.

My CE light started coming on intermittently (on, shortly after I pull out of the driveway, for about 10 seconds, then, off again) on very cold mornings. When it began, I immediately ordered O2 sensors. Just because it's intermittent, doesn't mean you shouldn't give it your attention, asap. I'm just waiting for a warm snap (no garage to work in) in order to change the O2's.

The O2's will degrade your gas mileage, if left unchanged. Their condition feeds information about other system components, so, change them soon. If you're shocked by the OE price, then, you can go to www.oxygensensors.com and choose either "splice ons" or OE Plug-ins. I ordered "splice ons" the first time, but decided I'd go the extra bucks for the plug-ins this time.

[IwantaSVX]

My CEL would come on when I was driving and my foot was in the gas. If I let off the gas the light went off.

The car is running fine once again but its starting harder than normal. It usually starts RIGHT up....now it is taking like 10 seconds.

I doubt it is not the Coolant Temp Sensor. I replaced it a few months ago. Plus I do not have the common fan running all the time or the REALLY hard starting/stalling.

Any ideas why the car is starting hard now? Would O2 sensors cause this?

[Aredubjay]

Originally posted by IwantaSVX
Would O2 sensors cause this?

Ignition is dependent upon oxygen + fuel mix. If the O2 Sensor, are not sensing the O2 correctly and sending an incorrect signal to the ECU, yes, it could cause the engine to take longer to take longer to start.

[zarmien]

check to see if the intake manifold is completly bolted down mine wasn't so I had horriable gas milage and performance till I noticed it

[Mr. Pockets]

Yeah, it sounds like you should replace the O2 sensors to start off. You said it was hesitating and running rich - if the O2 sensors aren't providing feedback to the ECU, it's missing some of the information it needs to properly mix the fuel and air.

Whether or not it's running fine now, I'd still replace them. After an episode like that, and the ECU telling you that they're both bad, what other clues do you need? It's only going to get worse and eventually those problems will cause other problems.

[IwantaSVX]

I'm going to replace both O2 Sensors within the next week. They will be ordered tomorrow. I just want to be sure this is what is causing my problem. I don't understand how the car can run like **** and it was running better than ever today. I have no experience with these sensors going. I would just think that once they go I would have serious runablility concerns that would not just disappear...or come and go. All day long today it was starting RIGHT up. I filled it up with gas at 250 miles it took 15 gallons....which is horrible. I usually get 340 miles to a 13-14 gallon fill up. I get a mile up the road after filling up and the CEL comes on so I let off the gas and it goes out.

The CEL only seems to come on when I am going up a hill. Like I said as soon as I let off the gas it goes off. The only exception being the other night when the car was running like it ran out of gas....and the light stayed on the entire time.

I will replace both O2 sensors and report back. I just hope this fixes the problem. We're not exactly talking about $15 sensors here and when you just start replacing stuff....it gets expensive.