SES light flashes when towing?

[ibm6gto]

searched for an hour but didnt find any results on this issue. I have a 2003 Sonoma sle ext cab 4x4 with 4.3L automatic 46,000 miles. I'm getting a ses light which flashes only when towing the boat. it's an aluminium boat weighing about 2000 lbs. If its a flat road and i take it easy accelerating there is no flashing ses light, but if it downshifts and gets over about 3500 rpm going up hills the light flashes. dealer thinks its a misfire and recommends replacing plugs, wires and distributor. anyone having this issue. any thoughts?? Thanks for any help

 

[Smoky02]

Have you looked at the MAF to see if its' claean?

 

[ibm6gto]

no i haven't i will check it out to see how it looks. what is a good cleaning agent to use on the MAF sensor? thanks for the help

 

[Smoky02]

I like using CRC MAF Cleaner, http://www.crc-canada.ca/Support/products_ss.aspx?FAM=CleanersDegreasers&FT=103&FV=14633

 

[lmleck]

Check fuel pressure. Should be btw 50 and 60, increase on acceleration.
Could be low, leaking fuel pressure regulator or fuel filter.
May be beginning to run lean on hard acceleration when towing.

 

[ibm6gto]

thanks a lot for the tips. I will try the MAF cleaner first then hook up to a friends trailer to test it out. put the boat is in storage today for 3 grueling months. i have access to a Tech 2 scanner so will be checking fuel pressure and lean status if the MAF cleaner doesnt do the trick. ill post back my results. looking foward to spending time on this forum, found a lot of good reading already.