p0174 and p0171

[alohamonte]

p0174 - System Too Lean (Bank 2)
p0741 - System Too Lean (Bank 1)

CEL came on today. I keep a scanner in the car and it read codes above. No drive ability issues detected from the driver's seat. I cleared the code and drove it another 40 miles and it hasn't come back.

I was going to start by changing the PVC value and elbow.

I run a Torq app as well and it detected a problem with "Spark" at the same time that CEL activated. So I will change out the spark plugs and inspect the wires for problems as well.

 

[chefduane]

Same exact codes on my same exact vehicle. For me it turned out to be upper and lower intake manifold gaskets. Symptoms were P0171/0174 and hard starts on colder mornings.
The gaskets tend to shrink over time (originals - about 179k when I changed them, now 203k) and are not able to expand back enough to fill the gap and seal the vacuum, hence the lean codes. Rock Auto has complete sets of uppers and lowers for less than $50 IIRC. About a 3 - 4 hour job depending on skill and tools, fairly easy tho.

 

[1998Exp]

If that's the SOHC, +1 on leaking intake manifold gaskets.
Don't know what 'spark' means. If there was a misfire, you'd get a code for that.
Don't know how you are going to inspect the wires. Unless you find burned spots, or they are brittle and falling apart, there'd be nothing visible, even if they are bad. Some spray water on them, watching for misfire or arcing. Can't vouch for this method. The only sure way to find out is to check the ignition waveform with an oscilloscope. However, if the wires are older than 5 years, unknown age, or iffy brand, I would just replace them, regardless of the results of any 'inspection'.

p0174 - System Too Lean (Bank 2)
p0741 - System Too Lean (Bank 1)

CEL came on today. I keep a scanner in the car and it read codes above. No drive ability issues detected from the driver's seat. I cleared the code and drove it another 40 miles and it hasn't come back.

I was going to start by changing the PVC value and elbow.

I run a Torq app as well and it detected a problem with "Spark" at the same time that CEL activated. So I will change out the spark plugs and inspect the wires for problems as well.